use display contents instead of setting a height (#18363)

src/Umbraco.Web.UI.Client/src/packages/core/modal/component/modal.element.ts

@@ -103,8 +103,7 @@ export class UmbModalElement extends UmbLitElement {
 		} else {
 			this.#modalRouterElement = document.createElement('div');
 			// Notice inline styling here is used cause the element is not appended into this elements shadowDom but outside and there by gets into the element via a slot.
-			this.#modalRouterElement.style.position = 'relative';
-			this.#modalRouterElement.style.height = '100%';
+			this.#modalRouterElement.style.display = 'contents';
 			new UmbContextBoundary(this.#modalRouterElement, UMB_ROUTE_CONTEXT).hostConnected();
 		}