Ignore MSW-only changes for PR builds on GitHub CI too

This extends the grandparent commit to apply to pull requests and not
only to the master builds.

.github/workflows/ci.yml

@@ -28,8 +28,12 @@ on:
       - 'distrib/**'
       - 'docs/**'
       - 'interface/**'
+      - 'include/msvc/**'
+      - 'include/wx/msw/**'
+      - 'src/wx/msw/**'
       - '*.md'
       - '*.yml'
+      - 'wxwidgets.props'
 
 jobs:
   build: