Update cimg/base Docker tag to v2023.12

Author: renovate[bot]

.circleci/config.yml

@@ -60,7 +60,7 @@ jobs:
   build_docker:
     resource_class: small
     docker:
-      - image: cimg/base:2023.04
+      - image: cimg/base:2023.12
     steps:
       - checkout
       - setup_remote_docker:
@@ -73,7 +73,7 @@ jobs:
   publish_docker:
     resource_class: small
     docker:
-      - image: cimg/base:2023.04
+      - image: cimg/base:2023.12
     steps:
       - checkout
       - setup_remote_docker: