chore(internal): bump mypy (#1839)

Author: stainless-app[bot]

Diff for: requirements-dev.lock

@@ -48,7 +48,7 @@ markdown-it-py==3.0.0
     # via rich
 mdurl==0.1.2
     # via markdown-it-py
-mypy==1.11.2
+mypy==1.13.0
 mypy-extensions==1.0.0
     # via mypy
 nodeenv==1.8.0