Merge #2340

2340: circle config changes to adjust for circleci deprecation of ubuntu 14.04 r=tiftran a=tiftran

Ref: https://circleci.com/docs/2.0/images/linux-vm/14.04-to-20.04-migration/

Co-authored-by: tiftran <ttran@mozilla.com>

.circleci/config.yml

@@ -132,7 +132,7 @@ jobs:
 
   docs-build:
     docker:
-      - image: circleci/python:3.9
+      - image: cimg/python:3.9
         auth:
           username: $DOCKER_USER
           password: $DOCKER_PASS
@@ -185,11 +185,11 @@ jobs:
 
   python-tests:
     docker:
-      - image: circleci/python:3.9-node-browsers
+      - image: cimg/python:3.9.12-node
         auth:
           username: $DOCKER_USER
           password: $DOCKER_PASS
-      - image: circleci/postgres:9.6
+      - image: cimg/postgres:9.6.24
         environment:
           POSTGRES_HOST_AUTH_METHOD: trust
         auth: