Look for gcov in Qt's MinGW

Author: pcolby

.github/workflows/build.yaml

@@ -487,7 +487,7 @@ jobs:
           - { toolchain: 'mingw', arch: x86-64, qt: '6.8.0',  aqtTools: 'tools_mingw1310' }
     steps:
       #- run: dir C:\ghcup\ghc /s '*gcov*'
-      #- run: dir D:/a/dokit/Qt /s '*gcov'
+      - run: dir D:/a/dokit/Qt /s '*gcov'
       - uses: actions/checkout@v4
       - name: Install host Qt for cross-compilation
         if: matrix.arch == 'arm64'