[PM-6575] Collection of page details might error when getting text content from field sibilings (#8169)

apps/browser/src/autofill/services/collect-autofill-content.service.ts

@@ -755,6 +755,9 @@ class CollectAutofillContentService implements CollectAutofillContentServiceInte
 
     // Prioritize capturing text content from elements rather than nodes.
     currentElement = currentElement.parentElement || currentElement.parentNode;
+    if (!currentElement) {
+      return textContentItems;
+    }
 
     let siblingElement = nodeIsElement(currentElement)
       ? currentElement.previousElementSibling