htmlinputelement: Update radio group validity logic for disconnected trees (#36431)

This PR updates the validity state revalidation behavior for radio input
elements, ensuring consistent logic regardless of tree connectivity.

---

**What’s changed:**  
- we now always update the validity state.
- Handled more edge cases for disconnected trees, shadow roots, and
cross-tree movement.
- Ensured that radio group updates still trigger when a parent is moved
into a different root.
- Updated test expectations in
`radio-disconnected-group-owner.html.ini`.

---

**Why this matters:**  
The updated logic aligns better with the [HTML
specification](https://html.spec.whatwg.org/multipage/input.html#radio-button-group),
especially regarding radio group behavior in disconnected trees or
shadow DOM.

These changes improve validity propagation in scenarios like:
- Appending inputs into a disconnected form
- Shadow roots acting as radio group containers
- Cross-tree movement of radio buttons

---

**Tests:**  
- Modified `radio-disconnected-group-owner.html.ini`
  - Removed a test that now passes
- Added a failing test expectation caused by a spec bug: the fragment
parsing algorithm uses the connected tree for HTML set via `innerHTML`,
affecting radio group computation

---

**Spec reference:**  
https://html.spec.whatwg.org/multipage/input.html#radio-button-group

---
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Signed-off-by: Emmanuel Paul Elom <elomemmanuel007@gmail.com>

components/script/dom/htmlinputelement.rs

@@ -1257,6 +1257,7 @@ impl HTMLInputElementMethods<crate::DomTypeHolder> for HTMLInputElement {
     // https://html.spec.whatwg.org/multipage/#dom-input-checked
     fn SetChecked(&self, checked: bool) {
         self.update_checked_state(checked, true);
+        update_related_validity_states(self, CanGc::note())
     }
 
     // https://html.spec.whatwg.org/multipage/#dom-input-readonly
@@ -1697,7 +1698,7 @@ fn radio_group_iter<'a>(
 ) -> impl Iterator<Item = DomRoot<HTMLInputElement>> + 'a {
     root.traverse_preorder(ShadowIncluding::No)
         .filter_map(DomRoot::downcast::<HTMLInputElement>)
-        .filter(move |r| &**r == elem || in_same_group(r, form, group, None))
+        .filter(move |r| &**r == elem || in_same_group(r, form, group, Some(root)))
 }
 
 fn broadcast_radio_checked(broadcaster: &HTMLInputElement, group: Option<&Atom>) {
@@ -2580,6 +2581,9 @@ impl VirtualMethods for HTMLInputElement {
         self.upcast::<Element>()
             .check_ancestors_disabled_state_for_form_control();
 
+        if self.input_type() == InputType::Radio {
+            self.radio_group_updated(self.radio_group_name().as_ref());
+        }
         update_related_validity_states(self, can_gc);
     }