improve literal handling in pyi generator (#5725)

Author: adhami3310

reflex/utils/pyi_generator.py

@@ -145,7 +145,7 @@ def _get_type_hint(
     res = ""
     args = get_args(value)
 
-    if value is type(None):
+    if value is type(None) or value is None:
         return "None"
 
     if rx_types.is_union(value):
@@ -425,10 +425,18 @@ def type_to_ast(typ: Any, cls: type) -> ast.expr:
     Returns:
         The AST representation of the type annotation.
     """
-    if typ is type(None):
+    if typ is type(None) or typ is None:
         return ast.Name(id="None")
 
     origin = get_origin(typ)
+    if origin is typing.Literal:
+        return ast.Subscript(
+            value=ast.Name(id="Literal"),
+            slice=ast.Tuple(
+                elts=[ast.Constant(value=val) for val in get_args(typ)], ctx=ast.Load()
+            ),
+            ctx=ast.Load(),
+        )
     if origin is UnionType:
         origin = typing.Union