Bump docker/build-push-action from 5 to 6 in the ci-dependencies group

Bumps the ci-dependencies group with 1 update: [docker/build-push-action](https://github.com/docker/build-push-action).


Updates `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
  dependency-group: ci-dependencies
...

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

.github/workflows/build.yaml

@@ -74,7 +74,7 @@ jobs:
       # If configured by the cache_config step, also cache the layers in
       # GitHub Actions.
       - name: Build image for linting and testing
-        uses: docker/build-push-action@v5
+        uses: docker/build-push-action@v6
         with:
           context: .
           file: ./Dockerfile

.github/workflows/deploy.yaml

@@ -45,7 +45,7 @@ jobs:
       # Build the final production image and push it to GHCR.
       # Tag it with both the short commit SHA and 'latest'.
       - name: Build final image
-        uses: docker/build-push-action@v5
+        uses: docker/build-push-action@v6
         with:
           context: .
           file: ./Dockerfile
@@ -78,7 +78,7 @@ jobs:
 
       # Push the base image to GHCR, with an inline cache manifest.
       - name: Push base image
-        uses: docker/build-push-action@v5
+        uses: docker/build-push-action@v6
         with:
           context: .
           file: ./Dockerfile
@@ -92,7 +92,7 @@ jobs:
 
       # Push the venv image to GHCR, with an inline cache manifest.
       - name: Push venv image
-        uses: docker/build-push-action@v5
+        uses: docker/build-push-action@v6
         with:
           context: .
           file: ./Dockerfile