Remove extraneous word

Co-authored-by: Sergey B Kirpichev <skirpichev@gmail.com>

Author: encukou

peps/pep-0820.rst

@@ -335,7 +335,7 @@ modify the slot array, nor any data it points to (recursively).
 After the function is done, the user is allowed to modify or deallocate the
 array, and any data it points to (recursively), unless it's explicitly marked
 as "static" (see ``PySlot_STATIC`` below).
-This means the interpreter needs typically needs to make a copy of all data
+This means the interpreter typically needs to make a copy of all data
 in the struct, including ``char *`` text.