Disable use of config.site file

Author: Luigi96

.github/workflows/build-windows.yml

@@ -181,6 +181,7 @@ jobs:
           # We need a minimal PATH on Windows
           # Set PATH to "", so just GITHUB_PATH is included
           PATH: ''
+          CONFIG_SITE: ''
         shell: env /usr/bin/bash --login -eo pipefail {0}
         if: ${{ inputs.dry-run == false }}