Add new api schema check workflow (#16143)

* add new file to separate out the schema check so that it is no longer
  part of CI check and won't cacuse the whole workflow to fail
* remove old API schema check from ci.yml

.github/workflows/ci.yml

@@ -38,12 +38,6 @@ jobs:
           - name: awx-collection
             command: /start_tests.sh test_collection_all
             coverage-upload-name: "awx-collection"
-          - name: api-schema
-            command: >-
-              /start_tests.sh detect-schema-change SCHEMA_DIFF_BASE_BRANCH=${{
-                github.event.pull_request.base.ref || github.ref_name
-              }}
-            coverage-upload-name: ""
 
     steps:
       - uses: actions/checkout@v4