Use most recent Elixir + Erlang versions only

Author: JesseHerrick

.github/workflows/ci.yml

@@ -9,8 +9,8 @@ jobs:
     name: Ex${{matrix.elixir}}/OTP${{matrix.otp}}
     strategy:
       matrix:
-        elixir: ["1.15.8", "1.16.3", "1.17.3", "1.18.2", "1.19.0-rc.0"]
-        otp: ["25.3.2", "26.2.5", "27.2.4"]
+        elixir: ["1.18.4", "1.19.0-rc.0"]
+        otp: ["27.3.4", "28.0"]
         exclude:
           - elixir: "1.15.8"
             otp: "27.2.4"