CI: Bump the Circle CI base Ubuntu image to the latest 20.04

The previous ones are going to be removed soon, plus the new ones
include all the fixes since then.

.circleci/config.yml

@@ -246,7 +246,7 @@ commands:
 executors:
   ubuntu:
     machine:
-      image: ubuntu-2004:202010-01
+      image: ubuntu-2004:2024.01.1
 
 jobs:
   basic:
@@ -307,7 +307,7 @@ jobs:
 
   arm:
     machine:
-      image: ubuntu-2004:202101-01
+      image: ubuntu-2004:2024.01.1
     resource_class: arm.medium
     steps:
       - checkout
@@ -318,7 +318,7 @@ jobs:
 
   arm-cares:
     machine:
-      image: ubuntu-2004:202101-01
+      image: ubuntu-2004:2024.01.1
     resource_class: arm.medium
     steps:
       - checkout