Merge pull request #595 from ably/ECO-5220/fix-python3.7-ci

[ECO-5220] Enforce `ubuntu-22.04` in CI to support python 3.7

Author: VeskeR

.github/workflows/check.yml

@@ -14,7 +14,7 @@ on:
 jobs:
   check:
 
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-22.04
     strategy:
       fail-fast: false
       matrix: