Tests: Opt out of Git mitigation of CVE-2022-24765

We are always a single user when running unit tests in the container.

Suppresses this error:

```
$ git submodule update --init --recursive --remote
fatal: detected dubious ownership in repository at '/__w/e107/e107'
To add an exception for this directory, call:

	git config --global --add safe.directory /__w/e107/e107
```

.github/workflows/test-unit.yml

@@ -119,6 +119,9 @@ jobs:
       run: composer update --prefer-dist --no-progress
       working-directory: ./e107_tests/
 
+    - name: Opt out of CVE-2022-24765 mitigation
+      run: git config --global safe.directory '*'
+
     - name: Download Git submodule dependencies
       run: git submodule update --init --recursive --remote