PhpUnit 13 support

[sirn-se]

Supporting PhpUnit v13.

As of v12, tests caused warnings;

No expectations were configured for the mock object for RobinIngelbrecht\PHPUnitCoverageTools\Exitter.
Consider refactoring your test code to use a test stub instead.
The #[AllowMockObjectsWithoutExpectations] attribute can be used to opt out of this check.

Adding expects to "exitter" mock resolved this.

Tested with phpunit/phpstan for php version 8.2, 8.3, 8.4 and 8.5.

[robiningelbrecht]

@sirn-se thanks for your contribution!

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 0.00%. Comparing base (a4d5e78) to head (9524278).
⚠️ Report is 17 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##             master   #25       +/-   ##
==========================================
- Coverage     99.39%     0   -99.40%     
==========================================
  Files             9     0        -9     
  Lines           330     0      -330     
==========================================
- Hits            328     0      -328     
+ Misses            2     0        -2     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.