chore: remove dynamic module (#2755)

This downgrades code under `./dynamic` from a Go module to a regular
package.

dynamic/Makefile

@@ -1,7 +1,7 @@
 build: bin
 	go build \
 		-o bin/pulumi-resource-terraform-provider \
-		github.com/pulumi/pulumi-terraform-bridge/dynamic
+		github.com/pulumi/pulumi-terraform-bridge/v3/dynamic
 
 install: build
 	pulumi plugin rm resource terraform-provider --all --yes

dynamic/README.md

@@ -206,7 +206,7 @@ A representative gRPC handler looks like this:
 // tfprotov6/provider.go
 import (
     "github.com/pulumi/pulumi-terraform-bridge/v3/pkg/vendored/tfplugin6"
-    "github.com/pulumi/pulumi-terraform-bridge/dynamic/internal/shim/protov6/translate"
+    "github.com/pulumi/pulumi-terraform-bridge/v3/dynamic/internal/shim/protov6/translate"
 )
 
 ...
@@ -270,7 +270,7 @@ These flags are hidden because they are expected to be used by other Pulumi proc
 ## Releasing & [`pulumi/pulumi-terraform-provider`](https://github.com/pulumi/pulumi-terraform-provider)
 
 The `pulumi-terraform-provider` codebase is located in
-[github.com/pulumi/pulumi-terraform-bridge/dynamic](https://github.com/pulumi/pulumi-terraform-bridge/blob/master/dynamic). However, the provider is released from
+[github.com/pulumi/pulumi-terraform-bridge/v3/dynamic](https://github.com/pulumi/pulumi-terraform-bridge/blob/master/dynamic). However, the provider is released from
 [github.com/pulumi/pulumi-terraform-provider](https://github.com/pulumi/pulumi-terraform-provider). There are 2 reasons for this:
 
 1. Pulumi's plugin discovery mechanism assumes that official plugins are located at