gh-138205: explicit mention to mmap.mmap.resize in "Porting to Python 3.15" notes (#143440)

Author: salty-horse

Doc/whatsnew/3.15.rst

@@ -1412,7 +1412,7 @@ that may require changes to your code.
   :func:`resource.setrlimit` and :func:`resource.prlimit` is now deprecated.
   (Contributed by Serhiy Storchaka in :gh:`137044`.)
 
-* :meth:`~mmap.mmap.resize` has been removed on platforms that don't support the
+* :meth:`mmap.mmap.resize` has been removed on platforms that don't support the
   underlying syscall, instead of raising a :exc:`SystemError`.
 
 * A resource warning is now emitted for an unclosed