Remove typing-extensions from dev dependencies (github#147)

typing-extensions is no longer needed as a dev dependency.

Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>

Author: harupy

python/pyproject.toml

@@ -42,7 +42,6 @@ dev = [
     "ty>=0.0.2",
     "pytest>=7.0.0",
     "pytest-asyncio>=0.21.0",
-    "typing-extensions>=4.0.0",
     "httpx>=0.24.0",
 ]