CI-mingw.yml: exclude clang++ on MINGW32 as it is no longer available (#644)

Author: firewave

.github/workflows/CI-mingw.yml

@@ -33,6 +33,9 @@ jobs:
         exclude:
           - msystem: CLANG64
             compiler: g++
+          # the mingw-w64-i686-clang package is no longer available
+          - msystem: MINGW32
+            compiler: clang++
       fail-fast: false
 
     runs-on: windows-2025