Bump docker/build-push-action from 4 to 6

Bumps [docker/build-push-action](https://github.com/docker/build-push-action) from 4 to 6.
- [Release notes](https://github.com/docker/build-push-action/releases)
- [Commits](docker/build-push-action@v4...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]>

Author: dependabot[bot]

.github/workflows/ci.yml

@@ -56,7 +56,7 @@ jobs:
           cp target/x86_64-unknown-linux-musl/release/controller .
 
       - name: Docker buildx and push with base features
-        uses: docker/build-push-action@v4
+        uses: docker/build-push-action@v6
         with:
           context: .
           cache-from: type=gha,scope=base
@@ -67,7 +67,7 @@ jobs:
           platforms: linux/amd64
 
       - name: Persist base image build to a tarball
-        uses: docker/build-push-action@v4
+        uses: docker/build-push-action@v6
         with:
           context: .
           platforms: linux/amd64
@@ -128,7 +128,7 @@ jobs:
           password: ${{ secrets.DOCKERHUB_TOKEN }}
 
       - name: Docker buildx and push with telemetry
-        uses: docker/build-push-action@v4
+        uses: docker/build-push-action@v6
         with:
           context: .
           cache-from: type=gha,scope=otel