Update build_wheels_linux.yml

Author: avdivan

.github/workflows/build_wheels_linux.yml

@@ -51,6 +51,7 @@ jobs:
       SDIST: ${{ matrix.build_sdist || 0 }}
       ENABLE_HEADLESS: ${{ matrix.without_gui }}
       ENABLE_CONTRIB: ${{ matrix.with_contrib }}
+      PIP_INDEX_URL: https://pypi.org/simple
 
     steps:
     - name: Cleanup