fix(admin-ui): Prevent product creation without variants

Fixes #2337

packages/admin-ui/src/lib/catalog/src/components/product-detail/product-detail.component.html

@@ -16,7 +16,7 @@
                 class="btn btn-primary"
                 *ngIf="isNew$ | async; else updateButton"
                 (click)="create()"
-                [disabled]="detailForm.invalid || detailForm.pristine"
+                [disabled]="detailForm.invalid || detailForm.pristine || createVariantsConfig.variants.length === 0"
             >
                 {{ 'common.create' | translate }}
             </button>