Add master branch and bump OTP in CI

Include 'master' alongside 'main' as workflow triggers, update otp-version from 27.0 to 28, and add rebar3-version set to "3". Leaves gleam-version unchanged and retains a commented elixir-version placeholder. These changes ensure CI runs on both branches and uses the newer OTP/rebar tooling.

Author: lupodevelop

.github/workflows/test.yml

@@ -2,7 +2,9 @@ name: test
 
 on:
   push:
-    branches: [main]
+    branches:
+      - master
+      - main
   pull_request:
 
 jobs:
@@ -12,8 +14,10 @@ jobs:
       - uses: actions/checkout@v4
       - uses: erlef/setup-beam@v1
         with:
-          otp-version: "27.0"
+          otp-version: "28"
           gleam-version: "1.14.0"
+          rebar3-version: "3"
+          # elixir-version: "1"
       - run: gleam deps download
       - run: gleam test
       - run: gleam format --check src test