fix: correct image tag format in GitHub Actions workflow

Author: Lars-

.github/workflows/docker-publish.yml

@@ -15,7 +15,7 @@ on:
 
 env:
   REGISTRY: ghcr.io
-  IMAGE_NAME: ${{ github.repository }}
+  IMAGE_NAME: opensource-digwebinterface
 
 jobs:
   build-and-push:
@@ -43,7 +43,7 @@ jobs:
         id: meta
         uses: docker/metadata-action@v5
         with:
-          images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
+          images: ${{ env.REGISTRY }}/${{ github.repository_owner }}/${{ env.IMAGE_NAME }}
           tags: |
             type=ref,event=branch
             type=ref,event=pr
@@ -67,6 +67,6 @@ jobs:
         if: github.event_name != 'pull_request'
         uses: actions/attest-build-provenance@v1
         with:
-          subject-name: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
+          subject-name: ${{ env.REGISTRY }}/${{ github.repository_owner }}/${{ env.IMAGE_NAME }}
           subject-digest: ${{ steps.build.outputs.digest }}
           push-to-registry: true