build(deps): bump docker/build-push-action from 5 to 6

Bumps [docker/build-push-action](https://github.com/docker/build-push-action) from 5 to 6.
- [Release notes](https://github.com/docker/build-push-action/releases)
- [Commits](https://github.com/docker/build-push-action/compare/v5...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>

.github/workflows/docker.yml

@@ -55,7 +55,7 @@ jobs:
         if: github.ref != 'refs/heads/master'
 
       - name: Build and push Docker image
-        uses: docker/build-push-action@2cdde995de11925a030ce8070c3d77a52ffcf1c0
+        uses: docker/build-push-action@15560696de535e4014efeff63c48f16952e52dd1
         with:
           push: true
           context: .

.github/workflows/tests.yml

@@ -325,7 +325,7 @@ jobs:
 
       - name: Build and push
         id: docker_build
-        uses: docker/build-push-action@v5
+        uses: docker/build-push-action@v6
         with:
           push: false
           context: .