FIX Don't throw console error if campaigns isn't installed

[GuySartorelli]

Fixes various failures in https://github.com/silverstripe/silverstripe-asset-admin/actions/runs/13803134628/job/38609073118 and https://github.com/silverstripe/silverstripe-cms/actions/runs/13803137179/job/38609088307 and https://github.com/silverstripe/silverstripe-elemental/actions/runs/13820952696

e.g.

[captured JavaScript error] Uncaught TypeError: Cannot read properties of undefined (reading 'schemaUrl') in http://localhost/_resources/vendor/silverstripe/admin/client/dist/js/vendor.js?m=1741750767:1:893686
STACKTRACE:
TypeError: Cannot read properties of undefined (reading 'schemaUrl')
    at M.renderEditor (<anonymous>:33:85316)
    at M.render (<anonymous>:33:86709)
    at As (http://localhost/_resources/vendor/silverstripe/admin/client/dist/js/vendor.js?m=1741750767:1:924348)
    at js (http://localhost/_resources/vendor/silverstripe/admin/client/dist/js/vendor.js?m=1741750767:1:924147)
    at Ou (http://localhost/_resources/vendor/silverstripe/admin/client/dist/js/vendor.js?m=1741750767:1:967185)
    at bl (http://localhost/_resources/vendor/silverstripe/admin/client/dist/js/vendor.js?m=1741750767:1:955484)
    at gl (http://localhost/_resources/vendor/silverstripe/admin/client/dist/js/vendor.js?m=1741750767:1:955412)
    at ml (http://localhost/_resources/vendor/silverstripe/admin/client/dist/js/vendor.js?m=1741750767:1:955275)
    at ol (http://localhost/_resources/vendor/silverstripe/admin/client/dist/js/vendor.js?m=1741750767:1:952110)
    at ul (http://localhost/_resources/vendor/silverstripe/admin/client/dist/js/vendor.js?m=1741750767:1:952492)
    And I click on the ".gallery__files .gallery-item__thumbnail" element # SilverStripe\BehatExtension\Context\BasicContext::iClickOnTheElement()
Saving screenshot into /home/runner/work/silverstripe-cms/silverstripe-cms/artifacts/screenshots/edit-a-page.feature_86.png
Saving HTML into /home/runner/work/silverstripe-cms/silverstripe-cms/artifacts/screenshots/zz_edit-a-page.feature_86.html
    And I press the "Insert file" button # SilverStripe\BehatExtension\Context\BasicContext::stepIPressTheButton()
      Insert file button not found
      Failed asserting that null is not null.

Issue

• Broken builds, merge-ups, and licenses .github#376