CI: ubuntu-20 no longer supported by Github Actions, bump to ubuntu-24 (processone#4281)

Author: badlop

.github/workflows/ci.yml

@@ -25,8 +25,8 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        otp: ['20.0', '25', '26', '27']
-    runs-on: ubuntu-20.04
+        otp: ['25', '26', '27']
+    runs-on: ubuntu-24.04
     services:
       redis:
         image: public.ecr.aws/docker/library/redis