`v_args` decorator retval type hint isn't correct, might as well be removed

[Kache]

Describe the bug

The return value type hint for v_args() isn't fully correct

lark/lark/visitors.py

Line 513 in 52ef09d

def v_args(inline: bool = False, meta: bool = False, tree: bool = False, wrapper: Optional[Callable] = None) -> Callable[[_DECORATED], _DECORATED]:

When -> Callable[[_DECORATED], _DECORATED] is removed entirely, i.e. the line changed to:

def v_args(inline: bool = False, meta: bool = False, tree: bool = False, wrapper: Optional[Callable] = None):

my typechecker (pyright/basedpyright, i.e. pylance from VSCode) properly infers the return type of transform()

To Reproduce

from lark import Transformer, v_args, Token, Tree

@v_args(meta=True)
class Foo(Transformer[Token, str]):
    def __init__(self):
        super().__init__()

    def foo(self, meta, args):
        return 'baz'


bar = Foo().transform(Tree('foo', []))
assert bar == 'baz'

with -> Callable[[_DECORATED], _DECORATED], type inference breaks and bar is considered Any | Unknown

without, bar is correctly considered str

[erezsh]

Thanks for reporting! You're welcome to submit a PR. Otherwise, I'll get to it somewhere down the line.

[Kache]

@erezsh, if you wouldn't mind taking a look: #1586