This PR fixes the pr check PR Testing wrongfully failing when the author commits code-only changes (when the bridge html output has not changed).

Example scenario when this happens:

• Create a PR
• The PR Testing check succeeds, generates the html preview and pushes it into https://github.com/RSS-Bridge/rss-bridge-tests
• A linter check fails e.g. a double white-space in a code line
• The PR author fixes the linting errors e.g. removes a single white-space
• The linter check succeeds
• The PR Testing check fails
  • PR Testing generates the exact same html preview, because the code change was irrelevant the the output. Because the html preview is the same, the git command git commit -m "$COMMIT_MESSAGE" fails with nothing to commit, working tree clean and the check gets marked as failed, even though the PR is actually fine
  • (if you would create a new PR with the same branch it would be marked as successful)

Same happens if you fix a typo in a variable name or any other code-only change.

If you look at the PR Testing action runs and filter by failure, around 50% failed because of nothing to commit, working tree clean, e.g.

• https://github.com/RSS-Bridge/rss-bridge/actions/runs/16418489279/job/46390421272
• https://github.com/RSS-Bridge/rss-bridge/actions/runs/16202571793/job/45745083484
• https://github.com/RSS-Bridge/rss-bridge/actions/runs/15414567717/job/43374310641
• https://github.com/RSS-Bridge/rss-bridge/actions/runs/16694754803/job/47257290739

It gets fixed by this PR by cancelling the Commit and push generated tests step with exit 0 when git commit fails.