Add --timeout to try to find hanging spec

.github/workflows/mingw.yml

@@ -121,7 +121,7 @@ jobs:
           [Console]::OutputEncoding = [System.Text.Encoding]::GetEncoding("IBM437")
           [Console]::InputEncoding  = [System.Text.Encoding]::GetEncoding("IBM437")
           ruby -v
-          ruby ../mspec/bin/mspec -I../../tool/lib -j
+          ruby ../mspec/bin/mspec -I../../tool/lib -j --timeout 60
 
       - uses: k0kubun/action-slack@v2.0.0
         with: