ci: bump ubuntu from 20.04 to 24.04 on runners

Author: gemidio

.github/workflows/continuous-integration.yml

@@ -5,7 +5,7 @@ on:
 jobs:
   testing:
     name: Tests
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-24.04
     strategy:
       matrix:
         php: