fix(core): add ariaRelevant to InternalsController

Author: bennypowers

.changeset/green-aliens-begin.md

@@ -0,0 +1,6 @@
+---
+"@patternfly/pfe-core": patch
+---
+
+`InternalsController`: add `ariaRelevant` property
+  

core/pfe-core/controllers/internals-controller.ts

@@ -134,6 +134,7 @@ export class InternalsController implements ReactiveController, ARIAMixin {
   @aria ariaPosInSet: string | null = null;
   @aria ariaPressed: string | null = null;
   @aria ariaReadOnly: string | null = null;
+  @aria ariaRelevant: string | null = null;
   @aria ariaRequired: string | null = null;
   @aria ariaRoleDescription: string | null = null;
   @aria ariaRowCount: string | null = null;