see if python 3.10 works with our downstreams (#7958)

Author: reaperhulk

.github/workflows/ci.yml

@@ -493,7 +493,7 @@ jobs:
           - mitmproxy
           - scapy
         PYTHON:
-          - 3.9
+          - '3.10'
     name: "Downstream tests for ${{ matrix.DOWNSTREAM }}"
     timeout-minutes: 15
     steps: