bpo-43760: Document PyThreadState.use_tracing removal (GH-28527) (GH-28529)

(cherry picked from commit f4ccb79)

Co-authored-by: Victor Stinner <[email protected]>

Author: miss-islington

Doc/whatsnew/3.10.rst

@@ -2301,3 +2301,6 @@ Removed
   These functions were undocumented, excluded from the limited C API, and were
   only used internally by the compiler.
   (Contributed by Victor Stinner in :issue:`43244`.)
+
+* The ``PyThreadState.use_tracing`` member has been removed to optimize Python.
+  (Contributed by Mark Shannon in :issue:`43760`.)