Update ci-build.yml

Remove old versions of ember

Author: chadhietala

.github/workflows/ci-build.yml

@@ -45,11 +45,6 @@ jobs:
       fail-fast: false
       matrix:
         ember-try-scenario:
-          - ember-lts-3.8
-          - ember-lts-3.12
-          - ember-lts-3.16
-          - ember-lts-3.20
-          - ember-lts-3.24
           - ember-lts-3.28
           - ember-release
           - ember-beta