apycot #1835791 computed_start_mode attribute is not actually computed [validation pending]

The computed_start_mode_attribute should be computed from start_mode (and the parent's computed_start_mode if start_mode is "inherited"). Instead the current hook modifies start_mode when it is set to inherited, and never updates refined test configs.

done in2.1.0
load left0.000
closed by#22d579c03d69 Fix computed_start_mode computation (closes #1835791)