CI: install aiohttp via [async] extra in test workflow

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: Abel Milash

.github/workflows/python-package.yml

@@ -30,7 +30,7 @@ jobs:
       run: |
         python -m pip install --upgrade pip
         python -m pip install flake8 black build diff-cover
-        python -m pip install -e .[dev]
+        python -m pip install -e .[dev,async]
     
     - name: Check format with black
       run: |