Bump docker/build-push-action from 4 to 5

Bumps [docker/build-push-action](https://github.com/docker/build-push-action) from 4 to 5.
- [Release notes](https://github.com/docker/build-push-action/releases)
- [Commits](docker/build-push-action@v4...v5)

---
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/docker.yml

@@ -86,7 +86,7 @@ jobs:
             org.oxidize-rb.ruby.platform=${{ matrix.platform.ruby_target }}
 
       - name: Docker build
-        uses: docker/build-push-action@v4
+        uses: docker/build-push-action@v5
         with:
           builder: ${{ steps.buildx.outputs.name }}
           context: ./docker
@@ -114,7 +114,7 @@ jobs:
           rb-sys-dock --platform ${{ matrix.platform.ruby_target }} --build || true
 
       - name: Docker push
-        uses: docker/build-push-action@v4
+        uses: docker/build-push-action@v5
         with:
           builder: ${{ steps.buildx.outputs.name }}
           context: ./docker