fix: args issue in __init__ of App class (reflex-dev#3140)

* (fix): remove '*args' from '__init__()' method of 'App', update
  docstrings and .pyi accordingly

reflex/app.py

@@ -160,11 +160,10 @@ class App(Base):
     # The radix theme for the entire app
     theme: Optional[Component] = themes.theme(accent_color="blue")
 
-    def __init__(self, *args, **kwargs):
+    def __init__(self, **kwargs):
         """Initialize the app.
 
         Args:
-            *args: Args to initialize the app with.
             **kwargs: Kwargs to initialize the app with.
 
         Raises:
@@ -176,7 +175,7 @@ def __init__(self, *args, **kwargs):
             raise ValueError(
                 "`connect_error_component` is deprecated, use `overlay_component` instead"
             )
-        super().__init__(*args, **kwargs)
+        super().__init__(**kwargs)
         base_state_subclasses = BaseState.__subclasses__()
 
         # Special case to allow test cases have multiple subclasses of rx.BaseState.

reflex/app.pyi

@@ -86,7 +86,6 @@ class App(Base):
     background_tasks: Set[asyncio.Task] = set()
     def __init__(
         self,
-        *args,
         stylesheets: Optional[List[str]] = None,
         style: Optional[ComponentStyle] = None,
         admin_dash: Optional[AdminDash] = None,