Only use clang on windows

Author: pifopi

.github/workflows/cpp-ci-serial-programs.yml

@@ -10,16 +10,15 @@ jobs:
       fail-fast: false
       matrix:
         os: [windows-2025, macos-13, ubuntu-24.04]
-        toolset: ['', '-T ClangCL']
+        toolset: ['']
         qt_version: ['6.9.0']
         include:
           - qt_version: '6.9.0'
             qt_version_major: '6'
             qt_modules: 'qtmultimedia qtserialport'
-        exclude:
-          - os: 'macos-13'
+
+          - os: 'windows-2025'
             toolset: '-T ClangCL'
-            # Excluded because macos default toolset is already clang
 
     steps:
     - uses: actions/checkout@v4