fix: use single registry for push-by-digest to fix manifest merge (#19)

Author: Mairuis

.github/workflows/build.yml

@@ -100,7 +100,7 @@ jobs:
           platforms: ${{ matrix.platform }}
           labels: ${{ steps.meta.outputs.labels }}
           outputs: |
-            type=image,name=${{ env.REGISTRY_IMAGE }},name=ghcr.io/${{ github.repository }},push-by-digest=true,name-canonical=true,push=${{ github.event_name != 'pull_request' }}
+            type=image,name=${{ env.REGISTRY_IMAGE }},push-by-digest=true,name-canonical=true,push=${{ github.event_name != 'pull_request' }}
             type=docker
           cache-from: type=gha,scope=build-${{ matrix.platform }}
           cache-to: type=gha,mode=max,scope=build-${{ matrix.platform }}
@@ -184,7 +184,7 @@ jobs:
         working-directory: /tmp/digests
         run: |
           docker buildx imagetools create $(jq -cr '.tags | map(select(startswith("ghcr.io")) | "-t " + .) | join(" ")' <<< "$DOCKER_METADATA_OUTPUT_JSON") \
-            $(printf 'ghcr.io/${{ github.repository }}@sha256:%s ' *)
+            $(printf '${{ env.REGISTRY_IMAGE }}@sha256:%s ' *)
 
       - name: Inspect image
         run: |