Bump docker/build-push-action from 6 to 7

Bumps [docker/build-push-action](https://github.com/docker/build-push-action) from 6 to 7.
- [Release notes](https://github.com/docker/build-push-action/releases)
- [Commits](https://github.com/docker/build-push-action/compare/v6...v7)

---
updated-dependencies:
- dependency-name: docker/build-push-action
  dependency-version: '7'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

.github/workflows/build-k3s.yaml

@@ -67,7 +67,7 @@ jobs:
       if: inputs.arch == 'arm64' || inputs.arch == 'amd64'
       env:
           DOCKER_BUILD_SUMMARY: false
-      uses: docker/build-push-action@v6
+      uses: docker/build-push-action@v7
       with:
         context: .
         file: ./Dockerfile.local
@@ -89,7 +89,7 @@ jobs:
       env:
         PLATFORM: ${{ inputs.arch == 'arm' && 'linux/arm/v7' || format('linux/{0}', inputs.arch) }}
         DOCKER_BUILD_SUMMARY: false
-      uses: docker/build-push-action@v6
+      uses: docker/build-push-action@v7
       with:
         context: .
         file: ./Dockerfile.local

.github/workflows/release.yml

@@ -166,7 +166,7 @@ jobs:
           cp ./dist/artifacts/data-* ./build/out
 
       - name: Build and push K3s runtime image
-        uses: docker/build-push-action@v6
+        uses: docker/build-push-action@v7
         with:
           context: .
           file: ./package/Dockerfile