MNT Don't test behat from other modules anymore (#615)

This module used to be used by those modules, so these behat runs
validated changes in graphql didn't break those modules.

They don't do that anymore, so these behat runs are pointless here.

.github/workflows/ci.yml

@@ -9,17 +9,3 @@ jobs:
   ci:
     name: CI
     uses: silverstripe/gha-ci/.github/workflows/ci.yml@v1
-    with:
-      extra_jobs: |
-        - php: 8.3
-          endtoend: true
-          endtoend_suite: asset-admin
-          endtoend_config: vendor/silverstripe/asset-admin/behat.yml
-        - php: 8.3
-          endtoend: true
-          endtoend_suite: versioned-admin
-          endtoend_config: vendor/silverstripe/versioned-admin/behat.yml
-        - php: 8.3
-          endtoend: true
-          endtoend_suite: silverstripe-elemental
-          endtoend_config: vendor/dnadesign/silverstripe-elemental/behat.yml