fix: update Python version requirement to 3.10+

BREAKING CHANGE: Python 3.8 and 3.9 are no longer supported

- MCP package requires Python >=3.10 (all versions from 0.9.1 to 1.9.3)
- Update setup.py to require Python >=3.10
- Update GitHub Actions to only test Python 3.10, 3.11, and 3.12
- Update README.md with correct Python version requirement
- Remove typing-extensions dependency (not needed for Python 3.10+)
- Remove Python 3.8/3.9 from classifiers

This resolves all GitHub Actions failures for Python 3.8/3.9 tests.

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

setup.py

@@ -18,13 +18,12 @@ setup(
     long_description=long_description,
     long_description_content_type="text/markdown",
     author="Fahad Gilani",
-    python_requires=">=3.8",
+    python_requires=">=3.10",
     py_modules=["gemini_server"],
     install_requires=[
         "mcp>=1.0.0",
         "google-generativeai>=0.8.0",
         "python-dotenv>=1.0.0",
-        "typing-extensions>=4.0.0;python_version<'3.10'",
     ],
     extras_require={
         "dev": [
@@ -43,8 +42,6 @@ setup(
         "Development Status :: 4 - Beta",
         "Intended Audience :: Developers",
         "Programming Language :: Python :: 3",
-        "Programming Language :: Python :: 3.8",
-        "Programming Language :: Python :: 3.9",
         "Programming Language :: Python :: 3.10",
         "Programming Language :: Python :: 3.11",
         "Programming Language :: Python :: 3.12",