bpo-43757: Document os.path.realpath(strict=True) in 3.10 whatsnew. (GH-26090) (#26099)

(cherry picked from commit d1560d2)

Co-authored-by: Barney Gale <[email protected]>

Co-authored-by: Barney Gale <[email protected]>

Author: miss-islington

Doc/whatsnew/3.10.rst

@@ -1089,6 +1089,14 @@ Add :data:`~os.O_EVTONLY`, :data:`~os.O_FSYNC`, :data:`~os.O_SYMLINK`
 and :data:`~os.O_NOFOLLOW_ANY` for macOS.
 (Contributed by Dong-hee Na in :issue:`43106`.)
 
+os.path
+-------
+
+:func:`os.path.realpath` now accepts a *strict* keyword-only argument. When set
+to ``True``, :exc:`OSError` is raised if a path doesn't exist or a symlink loop
+is encountered.
+(Contributed by Barney Gale in :issue:`43757`.)
+
 pathlib
 -------