Use ubuntu 20 for build as 22 doesn't support properly 3.6

Author: koen-serry

.github/workflows/python-publish.yml

@@ -57,7 +57,7 @@ jobs:
 
   deploy:
 
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
 
     steps:
     - uses: actions/checkout@v2