fix(ci): Clear cached .venv directory to ensure fresh install

The GitHub Actions cache was restoring a cached virtual environment
(.venv) with old code. This commit clears all caching layers:

1. Removes cached .venv directory (the main culprit)
2. Clears Python bytecode cache (.pyc files)
3. Clears UV cache directory

This forces uv sync to create a completely fresh virtual environment
with the latest source code changes, ensuring the authorization
parameter is picked up across all tool runtime providers.

.github/actions/setup-runner/action.yml

@@ -37,7 +37,14 @@ runs:
           echo "Exported UV environment variables for current and subsequent steps"
         fi
 
-        echo "Clearing Python bytecode cache and uv cache to ensure fresh install"
+        echo "Clearing cached virtual environment to ensure fresh install"
+        # Remove cached venv that may contain old code
+        if [ -d ".venv" ]; then
+          echo "Removing cached .venv directory"
+          rm -rf .venv
+        fi
+        
+        # Clear Python bytecode cache
         find . -type d -name "__pycache__" -exec rm -rf {} + 2>/dev/null || true
         find . -name "*.pyc" -delete 2>/dev/null || true
         
@@ -47,7 +54,7 @@ runs:
           rm -rf "$UV_CACHE_DIR"/*
         fi
 
-        echo "Syncing dependencies with uv"
+        echo "Syncing dependencies with uv (will create fresh venv)"
         uv sync --all-groups
 
         echo "Force reinstalling llama-stack from source to ensure latest changes"