updated ci to push to ghcr.io as well

Author: Sarke

.github/workflows/ci.yaml

@@ -42,4 +42,6 @@ jobs:
         with:
           file: ${{ matrix.dockerfile }}
           push: true
-          tags: ${{ matrix.tag }}
+          tags: |
+            ${{ matrix.dockerhub_tag }}
+            ghcr.io/${{ matrix.dockerhub_tag }}