Update elixir.yml to ubuntu-22.04

Author: manuel-rubio

.github/workflows/elixir.yml

@@ -18,7 +18,7 @@ jobs:
   build:
 
     name: Build and test
-    runs-on: ubuntu-24.04
+    runs-on: ubuntu-22.04
 
     steps:
     - uses: actions/checkout@v3