Fix mypy and pylint errors in js_action integration

- Add type: ignore for update_wrapper on _JsActionDescriptor
- Add type: ignore for JsAction callbacks passed to on() in fab/dropdown
- Replace ValueElement import with hasattr check to break cyclic import
  (nicegui.element -> nicegui.js_action -> nicegui.elements.mixins.value_element)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: evnchn

nicegui/elements/button_dropdown.py

@@ -57,7 +57,7 @@ def on_click(self, callback: Handler[ClickEventArguments]) -> Self:
         *Added in version 2.22.0*
         """
         if has_js_action(callback):
-            self.on('click', callback, [])
+            self.on('click', callback, [])  # type: ignore[arg-type]
         else:
             self.on('click', lambda _: handle_event(callback, ClickEventArguments(sender=self, client=self.client)), [])
         return self

nicegui/elements/fab.py

@@ -86,7 +86,7 @@ def __init__(self,
     def on_click(self, callback: Handler[ClickEventArguments]) -> Self:
         """Add a callback to be invoked when the action element is clicked."""
         if has_js_action(callback):
-            self.on('click', callback, [])
+            self.on('click', callback, [])  # type: ignore[arg-type]
         else:
             self.on('click', lambda _: handle_event(callback, ClickEventArguments(sender=self, client=self.client)), [])
         return self

nicegui/js_action.py

@@ -39,9 +39,8 @@ def _call_without_loopback(self) -> Any:
 
         Used when the action was already applied on the client via JavaScript.
         """
-        from .elements.mixins.value_element import ValueElement  # pylint: disable=import-outside-toplevel
         element = self._element
-        if isinstance(element, ValueElement):
+        if hasattr(element, '_send_update_on_value_change'):
             prev = element._send_update_on_value_change  # pylint: disable=protected-access
             element._send_update_on_value_change = False  # pylint: disable=protected-access
             try:
@@ -59,7 +58,7 @@ def __init__(self, method: Callable, js_handler_factory: Callable[[Any], str]) -
             raise TypeError(f'@js_action does not support async methods (got {method!r})')
         self._method = method
         self._js_handler_factory = js_handler_factory
-        functools.update_wrapper(self, method)
+        functools.update_wrapper(self, method)  # type: ignore[arg-type]
 
     def __get__(self, obj: Any, objtype: type | None = None) -> Any:
         if obj is None: