Test classes display cumulative execution time as 0.000s instead of the time sum of all executed tests

Reproduction steps:
1. Open the attached “ReproProject.zip“ project
2. Open the Test Runner window (Window > General > Test Runner)
3. Select the “Regular Category
4. Press “Run All tests”
5. Wait for the tests to finish and select any PlayModeTests class in the Test Runner
5. Observe the time at the bottom of the Test Runner window

Expected result: All PlayModeTests classes have their total execution time shown as 0.000s
Actual result: All PlayModeTests classes have their total execution time equal to the sum of all the tests an under that class

Reproducible with: 1.4.5 (2022.3.55f1, 6000.0.32f1, 6000.1.0a9), 2.0.1-pre.18 (6000.0.32f1)

Reproducible on: M1 Max MacOS 15.1.1
Not reproducible on: No other environment tested