There exists a test workflow definition `.github/workflows/test.yml`, introduced by https://github.com/openjdk/jtreg/commit/ba1fc9383547221faacd37d0a2b7b030b69b87f5
This file contains syntax errors and does not support common use-cases, like testing pushes to the master branch and pull requests.

Proposed steps.

1. Make the test workflow run by default on push events of the master branch.

2. Make the test workflow run by default on push events of pull requests.

3. On successful workflow runs on the master branch, attach the produced `jtreg` image to the run.