remove older Erlang versions

Author: joergen7

.github/workflows/ci.yml

@@ -13,7 +13,7 @@ jobs:
     runs-on: ${{matrix.os}}
     strategy:
       matrix:
-        otp: ['18.0', '19.0', '20.0', '21.0', '22.0', '23.0', '24.0', '25.0', '26.0', '27.0']
+        otp: ['24.0', '25.0', '26.0', '27.0']
         os: [ubuntu-latest]
     steps:
       - uses: actions/checkout@v4