chore: sciter-serde testing is disabled.

Because it always uses a published version, so what's the point?
Although, it'd be useful to test serde against the local version instead.

.appveyor.yml

@@ -93,6 +93,3 @@ test_script:
 
   - cargo test -p sciter-rs %FEATURES%
   - cargo test -p sciter-rs %FEATURES% --release
-
-  - cargo test -p sciter-serde %FEATURES%
-  - cargo test -p sciter-serde %FEATURES% --release

.github/workflows/cargo.yml

@@ -102,7 +102,6 @@ jobs:
         export PATH="$PATH:$SCITER_DEPS"
         cargo run --example first
         cargo test -p sciter-rs
-        cargo test -p sciter-serde
       env:
         SCITER_DEPS: ${{ runner.workspace }}
 

.travis.yml

@@ -93,7 +93,4 @@ script:
   - cargo test -p sciter-rs
   - cargo test -p sciter-rs --release
 
-  - cargo test -p sciter-serde
-  - cargo test -p sciter-serde --release
-
 after_script: set +e