PlayMode tests return no results when Test Runner is run again after Scene-Only Reload

How to reproduce:

1. Open the attached "IN-153267" project
2. Go to Window → General → Test Runner
3. In the Test Runner, select the "PlayMode" tab
4. At the bottom, press "Run All”
5. Observe the results in the Test Runner window
6. Press the "Run All" button again
7. Observe the results in the Test Runner window again

Actual result: All tests complete successfully and return results the first time, but after that, tests return no results
Expected result: All tests return results each time you run them

Reproducible with: 6000.6.0a6, 6000.6.1f1, 6000.7.0a3
Not reproducible with: 6000.0.82f1, 6000.3.23f1, 6000.6.0a5, 6000.7.0a6
Fixed in: 6000.7.0a4

Reproducible on: Windows 11
Not reproducible on: No other environments tested