Support Elixir 1.19/Erlang 28 in CI (#199)

Also bump actions/checkout.

Author: kianmeng

.github/workflows/ci.yml

@@ -13,13 +13,13 @@ jobs:
       fail-fast: false
       matrix:
         include:
-          - elixir: 1.14
-            otp: 24
-          - elixir: 1.18
-            otp: 27
+          - elixir: "1.14"
+            otp: "24"
+          - elixir: "1.19"
+            otp: "28"
             lint: lint
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
 
       - uses: erlef/setup-beam@v1
         with: