github: cmake suddenly defaults to ninja, explicitly define VS as generator

Author: m6w6

.github/workflows/cmake-build-ci.gen

@@ -111,6 +111,7 @@ function steps_setenv($os_vnd, $splat_map = null) {
         run: |
           echo "c:\msys64\usr\bin" | Out-File -FilePath $env:GITHUB_PATH -Encoding utf8 -Append
           echo "c:\msys64\mingw64\bin" | Out-File -FilePath $env:GITHUB_PATH -Encoding utf8 -Append
+          echo 'CMAKE_GENERATOR=Visual Studio 16 2019' | Out-File -FilePath $env:GITHUB_ENV -Encoding utf8 -Append
       - name: Prepare environment (MinGW)
         if: env.CC_VND == 'mingw'
         run: |

.github/workflows/cmake-build-ci.yml

@@ -374,6 +374,7 @@ jobs:
         run: |
           echo "c:\msys64\usr\bin" | Out-File -FilePath $env:GITHUB_PATH -Encoding utf8 -Append
           echo "c:\msys64\mingw64\bin" | Out-File -FilePath $env:GITHUB_PATH -Encoding utf8 -Append
+          echo 'CMAKE_GENERATOR=Visual Studio 16 2019' | Out-File -FilePath $env:GITHUB_ENV -Encoding utf8 -Append
       - name: Prepare environment (MinGW)
         if: env.CC_VND == 'mingw'
         run: |