fix(ui5-dynamic-page): validate aria-controls reference before rendering (#11033)

Problem:
Invalid ARIA attributes were being generated when the referenced header element wasn't available with the exact ID.

Solution:
Remove _accAttributesForHeaderActions because the header and the (pin/unpin/expand/collapse) actions exist in separate shadow DOMs.

Fixes: #10987

Author: NakataCode

packages/fiori/src/DynamicPage.ts

@@ -241,12 +241,6 @@ class DynamicPage extends UI5Element {
 		return !this._headerSnapped;
 	}
 
-	get _accAttributesForHeaderActions() {
-		return {
-			controls: `${this._id}-header` as Lowercase<string>,
-		};
-	}
-
 	get headerTabIndex() {
 		return (this._headerSnapped || this.showHeaderInStickArea) ? -1 : 0;
 	}

packages/fiori/src/DynamicPageTemplate.tsx

@@ -58,7 +58,6 @@ function headerActions(this: DynamicPage) {
 				snapped={this.headerSnapped}
 				pinned={this.headerPinned}
 				hidePinButton={this.hidePinButton}
-				accessibilityAttributes={this._accAttributesForHeaderActions}
 				onui5-expand-button-click={this.onExpandClick}
 				onui5-pin-button-click={this.onPinClick}
 				onui5-expand-button-hover-in={this.onExpandHoverIn}