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>

.github/workflows/test.yml

@@ -13,7 +13,7 @@ jobs:
       fail-fast: false
       matrix:
         os: [ubuntu-latest, macos-latest, windows-latest]
-        python-version: ['3.8', '3.9', '3.10', '3.11', '3.12']
+        python-version: ['3.10', '3.11', '3.12']
 
     steps:
     - uses: actions/checkout@v4

.github/workflows/test_debug.yml

@@ -1,60 +0,0 @@
-name: Debug Test Failures
-
-on:
-  workflow_dispatch:
-  push:
-    branches: [ main ]
-
-jobs:
-  debug-python38:
-    runs-on: ubuntu-latest
-    
-    steps:
-    - uses: actions/checkout@v4
-    
-    - name: Set up Python 3.8
-      uses: actions/setup-python@v5
-      with:
-        python-version: '3.8'
-    
-    - name: Show Python version
-      run: |
-        python --version
-        python -c "import sys; print(sys.version_info)"
-    
-    - name: Install basic dependencies
-      run: |
-        python -m pip install --upgrade pip setuptools wheel
-        pip --version
-    
-    - name: Try installing MCP
-      continue-on-error: true
-      run: |
-        pip install "mcp>=1.0.0" -v
-    
-    - name: Try installing google-generativeai
-      continue-on-error: true
-      run: |
-        pip install "google-generativeai>=0.8.0" -v
-    
-    - name: Install all dependencies
-      continue-on-error: true
-      run: |
-        pip install -e . -v
-        pip install -r requirements.txt -v
-    
-    - name: Show installed packages
-      run: |
-        pip list
-    
-    - name: Try importing modules
-      continue-on-error: true
-      run: |
-        python -c "import mcp" && echo "✓ mcp imported successfully" || echo "✗ Failed to import mcp"
-        python -c "import google.generativeai" && echo "✓ google.generativeai imported successfully" || echo "✗ Failed to import google.generativeai"
-        python -c "import gemini_server" && echo "✓ gemini_server imported successfully" || echo "✗ Failed to import gemini_server"
-    
-    - name: Run a simple test
-      continue-on-error: true
-      run: |
-        python -m pytest tests/test_imports.py -v