Fix CI

Author: bcardarella

.github/workflows/elixir.yml

@@ -14,7 +14,7 @@ env:
 jobs:
   build:
     name: Build and test
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@v3
     - name: Set up Elixir