chore(deps): bump docker/build-push-action from 6 to 7 (#13961)

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Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

.github/workflows/ghcr-build.yml

@@ -202,7 +202,7 @@ jobs:
           echo "EOF" >> "$GITHUB_OUTPUT"
       - name: Build and push runtime image ${{ matrix.base_image.image }}
         if: github.event.pull_request.head.repo.fork != true
-        uses: docker/build-push-action@v6
+        uses: docker/build-push-action@v7
         with:
           push: true
           tags: ${{ env.DOCKER_TAGS }}
@@ -215,7 +215,7 @@ jobs:
       # Forked repos can't push to GHCR, so we just build in order to populate the cache for rebuilding
       - name: Build runtime image ${{ matrix.base_image.image }} for fork
         if: github.event.pull_request.head.repo.fork
-        uses: docker/build-push-action@v6
+        uses: docker/build-push-action@v7
         with:
           tags: ghcr.io/${{ env.REPO_OWNER }}/runtime:${{ env.RELEVANT_SHA }}-${{ matrix.base_image.tag }}
           context: containers/runtime
@@ -350,7 +350,7 @@ jobs:
           # rather than a mutable branch tag like "main" which can serve stale cached layers.
           echo "OPENHANDS_DOCKER_TAG=${RELEVANT_SHA}" >> $GITHUB_ENV
       - name: Build and push Docker image
-        uses: docker/build-push-action@v6
+        uses: docker/build-push-action@v7
         with:
           context: .
           file: enterprise/Dockerfile