[Backport maintenance/4.0.x] [typing] Add sys check guard for typing.Self for python < 3.11 (#2912) [typing] Add sys check guard for typing.Self for python < 3.11 (#2911) Closes #2910 (cherry picked from commit 66df47f39e41b1820132e10c04fca6c8d4b3f644) Co-authored-by: Pierre Sassoulas <pierre.sassoulas@gmail.com>