[ci] Give ubuntu-latest a try again

Author: opoplawski

.github/workflows/main.yml

@@ -15,7 +15,7 @@ jobs:
   build:
     # The type of runner that the job will run on
     # ubuntu-latest fails: https://github.com/actions/runner/issues/2364
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-latest
     strategy:
       fail-fast: false
       matrix: