Weaken return type of Path.{glob,rglob} in 3.13 (#13223)

Since python/cpython#117589 (at least),
`Path.glob` and `Path.rglob` return an `Iterator` rather than a
`Generator`.

Author: cjwatson

stdlib/pathlib.pyi

@@ -129,12 +129,10 @@ class Path(PurePath):
         def read_text(self, encoding: str | None = None, errors: str | None = None) -> str: ...
 
     if sys.version_info >= (3, 13):
-        def glob(
-            self, pattern: str, *, case_sensitive: bool | None = None, recurse_symlinks: bool = False
-        ) -> Generator[Self, None, None]: ...
+        def glob(self, pattern: str, *, case_sensitive: bool | None = None, recurse_symlinks: bool = False) -> Iterator[Self]: ...
         def rglob(
             self, pattern: str, *, case_sensitive: bool | None = None, recurse_symlinks: bool = False
-        ) -> Generator[Self, None, None]: ...
+        ) -> Iterator[Self]: ...
     elif sys.version_info >= (3, 12):
         def glob(self, pattern: str, *, case_sensitive: bool | None = None) -> Generator[Self, None, None]: ...
         def rglob(self, pattern: str, *, case_sensitive: bool | None = None) -> Generator[Self, None, None]: ...