Fix warning in codeql-analysis.yml

GitHub action shows the following warning for build [3838973755](https://github.com/itsallcode/openfasttrace/actions/runs/3838973755):

```
1 issue was detected with this workflow: Please make sure that every branch in on.pull_request is also in on.push so that Code Scanning can compare pull requests against the state of the base branch.
```