Bump docker/build-push-action from 5 to 6

Bumps [docker/build-push-action](https://github.com/docker/build-push-action) from 5 to 6.
- [Release notes](https://github.com/docker/build-push-action/releases)
- [Commits](docker/build-push-action@v5...v6)

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

Signed-off-by: dependabot[bot] <[email protected]>

.github/workflows/build.yml

@@ -164,7 +164,7 @@ jobs:
             latest=${{ github.event.release.prerelease == false }}
 
       - name: Build Docker image
-        uses: docker/build-push-action@v5
+        uses: docker/build-push-action@v6
         with:
           context: .
           load: true
@@ -185,7 +185,7 @@ jobs:
           echo "PLATFORMS=linux/amd64,linux/arm64,linux/arm/v7" >> $GITHUB_ENV
 
       - name: Publish Docker image
-        uses: docker/build-push-action@v5
+        uses: docker/build-push-action@v6
         with:
           context: .
           platforms: ${{ env.PLATFORMS }}