Fix support of format units with the "e" prefix in nested tuples in PyArg_Parse

[serhiy-storchaka]

Bug report

PyArg_Parse format units es, et, es#, and et# are not correctly supported in nested tuples. This is because the code for parsing nested tuples counts the number of alphabetical symbols to determine the number of items. But "e" is a prefix and should not be counted.

Linked PRs

• gh-112438: Fix support of format units with the "e" prefix in nested tuples in PyArg_Parse #112439
• [3.12] gh-112438: Fix support of format units with the "e" prefix in nested tuples in PyArg_Parse (gh-112439) #112460
• [3.11] gh-112438: Fix support of format units with the "e" prefix in nested tuples in PyArg_Parse (gh-112439) #112461