ci: bump docker/build-push-action from 4.0.0 to 6.18.0

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

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

Author: dependabot[bot]

.github/workflows/docker.yaml

@@ -27,7 +27,7 @@ jobs:
           submodules: recursive
 
       - name: Build bpftool container image
-        uses: docker/build-push-action@3b5e8027fcad23fda98b2e3ac259d8d67585f671 # v4.0.0
+        uses: docker/build-push-action@263435318d21b8e681c14492fe198d362a7d2c83 # v6.18.0
         with:
           push: false
           tags: bpftool:latest