[programgen] Don't generate duplicate files

[lunaris]

The l2-provider-grpc-config, l2-provider-grpc-config-secret and l2-provider-grpc-config-schema-secret tests fail due to duplicate file generation e.g.

=== CONT  TestLanguage/l2-provider-grpc-config-secret
WARN: secret property listSecretBool1 (property of config) does not have an Output type
WARN: secret property listSecretBool2 (property of config) does not have an Output type
WARN: secret property listSecretBool3 (property of config) does not have an Output type
WARN: secret property listSecretInt1 (property of config) does not have an Output type
WARN: secret property listSecretInt2 (property of config) does not have an Output type
WARN: secret property listSecretInt3 (property of config) does not have an Output type
WARN: secret property listSecretNum1 (property of config) does not have an Output type
WARN: secret property listSecretNum2 (property of config) does not have an Output type
WARN: secret property listSecretNum3 (property of config) does not have an Output type
WARN: secret property listSecretString1 (property of config) does not have an Output type
WARN: secret property listSecretString2 (property of config) does not have an Output type
WARN: secret property listSecretString3 (property of config) does not have an Output type
WARN: secret property mapSecretBool1 (property of config) does not have an Output type
WARN: secret property mapSecretBool2 (property of config) does not have an Output type
WARN: secret property mapSecretBool3 (property of config) does not have an Output type
WARN: secret property mapSecretInt1 (property of config) does not have an Output type
WARN: secret property mapSecretInt2 (property of config) does not have an Output type
WARN: secret property mapSecretInt3 (property of config) does not have an Output type
WARN: secret property mapSecretNum1 (property of config) does not have an Output type
WARN: secret property mapSecretNum2 (property of config) does not have an Output type
WARN: secret property mapSecretNum3 (property of config) does not have an Output type
WARN: secret property mapSecretString1 (property of config) does not have an Output type
WARN: secret property mapSecretString2 (property of config) does not have an Output type
WARN: secret property mapSecretString3 (property of config) does not have an Output type
WARN: secret property objSecretBool1 (property of config) does not have an Output type
WARN: secret property objSecretBool2 (property of config) does not have an Output type
WARN: secret property objSecretBool3 (property of config) does not have an Output type
WARN: secret property objSecretInt1 (property of config) does not have an Output type
WARN: secret property objSecretInt2 (property of config) does not have an Output type
WARN: secret property objSecretInt3 (property of config) does not have an Output type
WARN: secret property objSecretNum1 (property of config) does not have an Output type
WARN: secret property objSecretNum2 (property of config) does not have an Output type
WARN: secret property objSecretNum3 (property of config) does not have an Output type
WARN: secret property objSecretString1 (property of config) does not have an Output type
WARN: secret property objSecretString2 (property of config) does not have an Output type
WARN: secret property objSecretString3 (property of config) does not have an Output type
WARN: secret property secretBool1 (property of config) does not have an Output type
WARN: secret property secretBool2 (property of config) does not have an Output type
WARN: secret property secretBool3 (property of config) does not have an Output type
WARN: secret property secretInt1 (property of config) does not have an Output type
WARN: secret property secretInt2 (property of config) does not have an Output type
WARN: secret property secretInt3 (property of config) does not have an Output type
WARN: secret property secretNum1 (property of config) does not have an Output type
WARN: secret property secretNum2 (property of config) does not have an Output type
WARN: secret property secretNum3 (property of config) does not have an Output type
WARN: secret property secretString1 (property of config) does not have an Output type
WARN: secret property secretString2 (property of config) does not have an Output type
WARN: secret property secretString3 (property of config) does not have an Output type
panic: fatal: An assertion has failed: duplicate file: src/main/java/com/pulumi/configgrpc/inputs/TsecretInt2.java

goroutine 65 [running]:
github.com/pulumi/pulumi/sdk/v3/go/common/util/contract.failfast(...)
        /home/will/go/pkg/mod/github.com/pulumi/pulumi/sdk/[email protected]/go/common/util/contract/failfast.go:23
github.com/pulumi/pulumi/sdk/v3/go/common/util/contract.Assertf(0x40?, {0x11be26b?, 0xc0004fb040?}, {0xc000b0a4d8?, 0x10?, 0xc0004fb000?})
        /home/will/go/pkg/mod/github.com/pulumi/pulumi/sdk/[email protected]/go/common/util/contract/assert.go:35 +0xe8
github.com/pulumi/pulumi-java/pkg/codegen/java.fs.add(0xc00063d080, {0xc0004fb040, 0x3b}, {0xc000961080, 0x55a, 0x580})
        /home/will/git/pulumi/pulumi-java-main/pkg/codegen/java/gen.go:1779 +0xc5
github.com/pulumi/pulumi-java/pkg/codegen/java.(*modContext).gen.func1({{0xc0008ba200, 0x3, 0x4}, {0xc0004344f7, 0x6}}, {0xc0008b7c00?, 0xb?}, {0xc000960b00, 0x55a})
        /home/will/git/pulumi/pulumi-java-main/pkg/codegen/java/gen.go:1821 +0x3e8
github.com/pulumi/pulumi-java/pkg/codegen/java.(*modContext).gen.func2({{0xc0008ba200, 0x3, 0x4}, {0xc0004344f7, 0x6}}, {0xc0008b7c00, 0xb}, 0x413fbb?)
        /home/will/git/pulumi/pulumi-java-main/pkg/codegen/java/gen.go:1829 +0x15a
github.com/pulumi/pulumi-java/pkg/codegen/java.(*modContext).gen(0xc00071afc0, 0xc00063d080)
        /home/will/git/pulumi/pulumi-java-main/pkg/codegen/java/gen.go:2008 +0x1324
github.com/pulumi/pulumi-java/pkg/codegen/java.GeneratePackage({0x11c0613?, 0xb?}, 0xc000944000, 0x0, 0xc00069f0e0, 0x0)
        /home/will/git/pulumi/pulumi-java-main/pkg/codegen/java/gen.go:2296 +0x7e5
github.com/pulumi/pulumi-java/pkg/cmd/pulumi-language-java.(*javaLanguageHost).GeneratePackage(0x1bd9d10?, {0x1179160?, 0xc0005a28e8?}, 0xc000395d50)
        /home/will/git/pulumi/pulumi-java-main/pkg/cmd/pulumi-language-java/main.go:744 +0x472
github.com/pulumi/pulumi/sdk/v3/proto/go._LanguageRuntime_GeneratePackage_Handler({0x1179160, 0xc0003302d0}, {0x13d27a8, 0xc00069ea20}, 0xc00027e080, 0x0)
        /home/will/go/pkg/mod/github.com/pulumi/pulumi/sdk/[email protected]/proto/go/language_grpc.pb.go:565 +0x1a6
google.golang.org/grpc.(*Server).processUnaryRPC(0xc0004e8200, {0x13d27a8, 0xc00069e990}, {0x13d9540, 0xc0009441a0}, 0xc0003a7200, 0xc00041c720, 0x1bf10b0, 0x0)
        /home/will/go/pkg/mod/google.golang.org/[email protected]/server.go:1394 +0xe49
google.golang.org/grpc.(*Server).handleStream(0xc0004e8200, {0x13d9540, 0xc0009441a0}, 0xc0003a7200)
        /home/will/go/pkg/mod/google.golang.org/[email protected]/server.go:1805 +0xe8b
google.golang.org/grpc.(*Server).serveStreams.func2.1()
        /home/will/go/pkg/mod/google.golang.org/[email protected]/server.go:1029 +0x8b
created by google.golang.org/grpc.(*Server).serveStreams.func2 in goroutine 44
        /home/will/go/pkg/mod/google.golang.org/[email protected]/server.go:1040 +0x125
FAIL    github.com/pulumi/pulumi-java/pkg/cmd/pulumi-language-java      10.991s
FAIL