ghcr: try logging in as repo owner instead of PR actor

Author: vszakats

.github/workflows/build_ci_multi.yml

@@ -20,7 +20,7 @@ jobs:
       - name: 'login ghcr.io'
         uses: redhat-actions/podman-login@4934294ad0449894bcd1e9f191899d7292469603 # v1.7
         with:
-          username: ${{ github.actor }}
+          username: ${{ github.repository_owner }}
           password: ${{ secrets.GITHUB_TOKEN }}
           registry: ghcr.io/${{ github.repository_owner }}
 
@@ -30,7 +30,7 @@ jobs:
     steps:
       - name: "login ghcr.io"
         env:
-          REGISTRY_USER: '${{ github.actor }}'
+          REGISTRY_USER: '${{ github.repository_owner }}'
           REGISTRY_TOKEN: '${{ secrets.GITHUB_TOKEN }}'
           IMAGE_REGISTRY: 'ghcr.io/${{ github.repository_owner }}'
         run: |