Bump docker/build-push-action from 3 to 4 (#187)

Bumps [docker/build-push-action](https://github.com/docker/build-push-action) from 3 to 4.
- [Release notes](https://github.com/docker/build-push-action/releases)
- [Commits](docker/build-push-action@v3...v4)

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

.github/workflows/tests.yml

@@ -40,7 +40,7 @@ jobs:
  - name: Checkout the repository
  uses: actions/[email protected]
  - name: Build
- uses: docker/build-push-action@v3
+ uses: docker/build-push-action@v4
  with:
  context: .
  push: false