The following are added to the internal C-API:
* _PyErr_FormatV()
* _PyErr_SetModuleNotFoundError()
* _PyXIData_GetNotShareableErrorType()
* _PyXIData_FormatNotShareableError()
We also drop _PyXIData_lookup_context_t and _PyXIData_GetLookupContext().
The subinterpreter tests have data races (see gh-129824).
TSAN attempts to intercept some of the fatal signals, which can lead to
bogus reports. We could possibly handle these via TSAN_OPTIONS, but it's
simpler to just skip those tests -- they're not multithreaded anyways.
Eric Snow