[3.12] GH-119054: Fix pathlib docs subtitle word order (#121167)

When backporting GH-120505 to 3.12, I accidentally transposed
"Permissions and ownership" into "Ownership and permissions".
Swap it back for consistency with 3.13 and main.

Doc/library/pathlib.rst

@@ -1473,7 +1473,7 @@ Renaming and deleting
    Remove this directory.  The directory must be empty.
 
 
-Ownership and permissions
+Permissions and ownership
 ^^^^^^^^^^^^^^^^^^^^^^^^^
 
 .. method:: Path.owner()