Reconfiguring tests doesn't update Testing panel

[Yoyokrazy]

Testing #21092

When reconfiguring tests from pytest -> unittest, the test panel doesn't automatically refresh. The refresh test button also just leaves the pytest header remaining at the top of the tree, rather than updating to the unittest filtered tests.

Reloading updates the testing panel to the correct output.

[eleanorjboyd]

Seeing a similar result right now on our current testing panel. I included a recording of what happens on insiders without the rewrite turned with the same steps. Therefore this is a bug but not a regression in functionality from the current testing experience.

switch_test_types_release_v.mov

[eleanorjboyd]

Looking for community feedback here, do people often switch between the testing infrastructures and run into this problem?

[eleanorjboyd]

use case too small and would require too much work to be a priority