pstats.FunctionProfile.ncalls should be str (#8712)

Correctly annotate `pstats.FunctionProfile.ncalls` as `str` instead of `int`.

Since this change introduces a difference between typeshed and CPython, add a comment pointing that out and linking to this PR.

Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>

stdlib/pstats.pyi

@@ -30,7 +30,8 @@ if sys.version_info >= (3, 9):
 
     @dataclass(unsafe_hash=True)
     class FunctionProfile:
-        ncalls: int
+        # Note: the annotation in the CPython codebase is "int", but the annotation in CPython is wrong! See #8712
+        ncalls: str
         tottime: float
         percall_tottime: float
         cumtime: float