CI: Skip GHC 9.6 on Windows

The proto-lens protoc plugin currently crashes with an access violation:

```
ERROR: C:/_bzl/33jjwvv5/external/stackage/BUILD.bazel:772:22: HaskellCabalLibrary @stackage//:language-c [for tool] failed: (Exit 1): cabal_wrapper.exe failed: error executing command (from target @stackage//:language-c)
  cd /d C:/_bzl/33jjwvv5/execroot/rules_haskell_tests
  SET CC_WRAPPER_CC_PATH=external/rules_haskell_ghc_windows_amd64/mingw/bin/clang
    SET CC_WRAPPER_CPU=x64_windows
    SET CC_WRAPPER_PLATFORM=windows
    SET LANG=C.UTF-8
    SET PATH=bazel-out/x64_windows-opt-exec-2B5CBBC6/bin/external/stackage/happy-1.20.1.1/_install/bin;bazel-out/x64_windows-opt-exec-2B5CBBC6/internal/_middlemen;bazel-out/x64_windows-opt-exec-2B5CBBC6/bin/external/alex/_install/bin;bazel-out/x64_windows-opt-exec-2B5CBBC6/internal/_middlemen;C:/Program Files/Git/usr/bin
    SET RULES_HASKELL_DOCDIR_PATH=external/rules_haskell_ghc_windows_amd64/doc/html/libraries/base-4.18.0.0
    SET RULES_HASKELL_GHC_PATH=external/rules_haskell_ghc_windows_amd64/bin/ghc-9.6.2.exe
    SET RULES_HASKELL_GHC_PKG_PATH=external/rules_haskell_ghc_windows_amd64/bin/ghc-pkg-9.6.2.exe
    SET RULES_HASKELL_LIBDIR_PATH=external/rules_haskell_ghc_windows_amd64/lib
  bazel-out\x64_windows-opt-exec-2B5CBBC6\bin\external\rules_haskell\haskell\cabal_wrapper.exe bazel-out/x64_windows-opt-exec-2B5CBBC6/bin/external/stackage/language-c_cabal_wrapper_args.json

Access violation in generated code when executing data at 0x7ff75714e360

 Attempting to reconstruct a stack trace...

   Frame	Code address
 * 0x6f166fd5d0	0x7ff75714e360
 * 0x6f166fd5d8	0x7ffe00000a77
 * 0x6f166fd5e0	0x2235758bcc0
```

Author: avdv

.github/workflows/workflow.yaml

@@ -170,6 +170,9 @@ jobs:
             bzlmod: true
           - ghc: 9.6.2
             bzlmod: true
+          # currently proto-lens-protoc fails with an access violation on Windows
+          - ghc: 9.6.2
+            os: windows-latest
     env:
       # prevent auto-detection of system compilers on Windows
       BAZEL_DO_NOT_DETECT_CPP_TOOLCHAIN: ${{ matrix.os == 'windows-latest' && 1 || 0 }}