fix(ui): undefined access with polymorphic joins and fix joins test config (#14057)

Currently integration / e2e tests on `main` fail because of this PR
https://github.com/payloadcms/payload/pull/12738

test/joins/collections/Categories.ts

@@ -2,9 +2,8 @@ import type { CollectionConfig } from 'payload'
 
 import { ValidationError } from 'payload'
 
-import { categoriesSlug, hiddenPostsSlug, postsSlug } from '../shared.js'
+import { categoriesSlug, hiddenPostsSlug, postsSlug, versionsSlug } from '../shared.js'
 import { singularSlug } from './Singular.js'
-import { versionsSlug } from './Versions.js'
 
 export const Categories: CollectionConfig = {
   slug: categoriesSlug,

test/joins/e2e.spec.ts

@@ -429,7 +429,7 @@ describe('Join Field', () => {
     await expect(joinField).toBeVisible()
 
     const editButton = joinField.locator(
-      'tbody tr:first-child td:nth-child(2) button.drawer-link__doc-drawer-toggler',
+      'tbody tr:first-child td:nth-child(1) button.drawer-link__doc-drawer-toggler',
     )
 
     await expect(editButton).toBeVisible()