Revert to aiohttp v3.8.6

.github/workflows/testing.yml

@@ -17,7 +17,7 @@ jobs:
 
     strategy:
       matrix:
-        python-version: ["3.7", "3.8", "3.9", "3.10", "3.11", "3.12"]
+        python-version: ["3.7", "3.8", "3.9", "3.10", "3.11"]
 
     steps:
     - uses: actions/checkout@v3

requirements.txt

@@ -2,7 +2,7 @@ uvicorn==0.22.0  # v0.22.0 is the last to support Python 3.7
 fastapi==0.103.1
 python-multipart==0.0.6
 websockets==11.0.3
-aiohttp==3.9.0b0
+aiohttp==3.8.6,<3.9
 async-timeout==4.0.3
 aiofiles==23.2.1
 Jinja2>=3.1.2,<3.2