Bump docker/build-push-action from 2 to 6 (#9)

Bumps [docker/build-push-action](https://github.com/docker/build-push-action) from 2 to 6.
- [Release notes](https://github.com/docker/build-push-action/releases)
- [Commits](docker/build-push-action@v2...v6)

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

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

.github/workflows/run-tests.yaml

@@ -36,7 +36,7 @@ jobs:
       -
         name: Build docker image
         id: docker_build
-        uses: docker/build-push-action@v2
+        uses: docker/build-push-action@v6
         with:
           context: ./${{ matrix.context }}
           file: ${{ matrix.context }}/Dockerfile-${{ matrix.dockerfile }}
@@ -57,7 +57,7 @@ jobs:
         if: ${{ github.event_name == 'push' }}
       -
         name: Push
-        uses: docker/build-push-action@v2
+        uses: docker/build-push-action@v6
         with:
           context: ./${{ matrix.context }}
           file: ${{ matrix.context }}/Dockerfile-${{ matrix.dockerfile }}