Fix pypi release image (#399)

Co-authored-by: Gunnar Atli Thoroddsen <Error: gh: Not Found (HTTP 404)gh: This API operation needs the user scope. To request it, run:  gh auth refresh -h github.com -s user>

Author: gatli

.circleci/config.yml

@@ -76,7 +76,7 @@ jobs:
 
   pypi_publish:
     docker:
-      - image: cimg/python:3.7-buster
+      - image: cimg/python:3.7
     steps:
       - checkout # checkout source code to working directory
       - run: