Fix conditions for publishing the container

The workflow isn't run on pushes for main, thus the previous condition didn't
make much sense. Instead, we want to push the containers on schedule or
when the workflow is run manually.

.github/workflows/build_containers.yml

@@ -57,15 +57,15 @@ jobs:
             FROM=${{ matrix.distribution.base }}
 
       - name: Log in to the Container registry
-        if: ${{ github.event_name == 'push' && github.ref == 'refs/heads/main' }}
+        if: ${{ github.event_name == 'workflow_dispatch' || github.event_name == 'schedule' }}
         uses: redhat-actions/podman-login@v1
         with:
           registry: ${{ env.REGISTRY }}
           username: ${{ github.actor }}
           password: ${{ secrets.GITHUB_TOKEN }}
 
       - name: Push to GitHub Container Repository
-        if: ${{ github.event_name == 'push' && github.ref == 'refs/heads/main' }}
+        if: ${{ github.event_name == 'workflow_dispatch' || github.event_name == 'schedule' }}
         uses: redhat-actions/push-to-registry@v2
         with:
           image: ${{ env.IMAGE_NAME }}