Fix condition for installing Msys2 on Windows

Author: andreasbuhr

.github/workflows/cmake.yml

@@ -414,7 +414,7 @@ jobs:
     - uses: actions/checkout@v3
 
     - name: "Install Msys2"
-      if: (startsWith(matrix.config.os, 'windows-2019') && contains(matrix.config.mingw, 'MINGW'))
+      if: (startsWith(matrix.config.os, 'windows-20') && contains(matrix.config.mingw, 'MINGW'))
       uses: msys2/setup-msys2@v2
       with:
         msystem: ${{ matrix.config.mingw }}