ci: Maybe codespell ignore FirstT

Can't tell if this means `FirstT` will match the entry `firstt`, but preserve the `firstt` fix (https://github.com/codespell-project/codespell#ignoring-words)

(#2572 (comment))

Author: dangotbanned

.pre-commit-config.yaml

@@ -19,7 +19,7 @@ repos:
   hooks:
     - id: codespell
       files: \.(py|rst|md)$
-      args: [--ignore-words-list=ser]
+      args: [--ignore-words-list=ser,FirstT]
       exclude: ^docs/api-completeness.md$
 -   repo: https://github.com/pycqa/flake8
     rev: '7.2.0'  # todo: remove once https://github.com/astral-sh/ruff/issues/458 is addressed