Resolve #3110831 "Cannot un disable a 10 3"

Relates to #3110831. This MR rebases the work on !1474 to work with Drupal 10.3.

core/modules/jsonapi/src/ResourceType/ResourceTypeBuildEvent.php

@@ -151,4 +151,19 @@ public function disableField(ResourceTypeField $field) {
     }
   }
 
+  /**
+   * Enables the given field on the resource type to be built.
+   *
+   * @param \Drupal\jsonapi\ResourceType\ResourceTypeField $field
+   *   The field for which to set a public name.
+   */
+  public function enableField(ResourceTypeField $field): void {
+    foreach ($this->fields as $index => $value) {
+      if ($field === $value) {
+        $this->fields[$index] = $value->enabled();
+        return;
+      }
+    }
+  }
+
 }