ci: try msys2 -c

Author: Berrysoft

.github/workflows/libloading.yml

@@ -59,8 +59,7 @@ jobs:
           install: ${{ matrix.package }}
           update: true
           location: C:/M
-      - run: echo "${{ matrix.mingw_path }}" | Out-File -FilePath $env:GITHUB_PATH -Append
-      - run: cargo test --target ${{ matrix.rust_target }}
+      - run: msys2 -c "cargo test --target ${{ matrix.rust_target }}"
         env:
           TARGET: ${{ matrix.rust_target }}