fix(ci): update mypy target to Python 3.10

Python 3.9 reached EOL in October 2025 and newer mypy versions
no longer accept it as a python_version target.

Co-authored-by: Cursor <cursoragent@cursor.com>

Author: Imran Kocabiyik

pyproject.toml

@@ -120,7 +120,7 @@ select = [
 ]
 
 [tool.mypy]
-python_version = "3.9"
+python_version = "3.10"
 exclude = ["^\\.venv/"]
 warn_return_any = true
 warn_unused_configs = true