Update CI to install [ai-features,dev] instead of [ai-copilot,dev]

The [ai-copilot] extra has been replaced by [ai-features] which
includes both AI Copilot and MCP dependencies.

.github/workflows/testing.yml

@@ -31,7 +31,7 @@ jobs:
     - name: Install dependencies
       run: |
         python -m pip install --upgrade pip
-        python -m pip install .[ai-copilot,dev]
+        python -m pip install .[ai-features,dev]
 
     - name: Install Windows specific dependencies
       if: runner.os == 'Windows'