Bump docker/build-push-action from 6.15.0 to 6.18.0

Bumps [docker/build-push-action](https://github.com/docker/build-push-action) from 6.15.0 to 6.18.0.
- [Release notes](https://github.com/docker/build-push-action/releases)
- [Commits](docker/build-push-action@v6.15.0...v6.18.0)

---
updated-dependencies:
- dependency-name: docker/build-push-action
  dependency-version: 6.18.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

.github/workflows/docker.yml

@@ -48,7 +48,7 @@ jobs:
         # Build and push Docker image
         # https://github.com/docker/build-push-action
         name: Build and push Docker image
-        uses: docker/build-push-action@v6.15.0
+        uses: docker/build-push-action@v6.18.0
         with:
           # Only push containers to the registry on GitHub pushes,
           # not pull requests. GitHub won't let a rogue PR create a container