Trac #34859: sagelib: Remove unnecessary import of typing_extensions

see also #34831

URL: https://trac.sagemath.org/34859
Reported by: mkoeppe
Ticket author(s): Matthias Koeppe
Reviewer(s): John Palmieri

Author: Release Manager

src/sage/dynamics/arithmetic_dynamics/projective_ds.py

@@ -52,7 +52,6 @@ class initialization directly.
 #                  https://www.gnu.org/licenses/
 # ****************************************************************************
 
-from typing_extensions import final
 from sage.arith.misc import is_prime
 from sage.calculus.functions import jacobian
 from sage.categories.fields import Fields