Updates runner to 24.04 and elixir to 1.18 (#191)

Author: capitalist

.github/workflows/ci.yml

@@ -6,16 +6,16 @@ on:
       - main
 jobs:
   test:
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-24.04
     env:
       MIX_ENV: test
     strategy:
       fail-fast: false
       matrix:
         include:
-          - elixir: 1.11
-            otp: 21
-          - elixir: 1.17
+          - elixir: 1.14
+            otp: 24
+          - elixir: 1.18
             otp: 27
             lint: lint
     steps: