How do unwrap (The problem reminds of rust) a type hint in python? Or in other words how to turn a Variable of type list[Optional[str]] into list[str]?

Problem:

I made a litte function to explain my problem.

So i start with a empty list but at a certain point (called Point B here) i want to pass my list to some further Processing in my code. But only if it has values in it. But Pylance shows me some Error. Even thought i know at this point the list ca not be empty. So do i init a new vaiable? Pylance wants me to wrap the argument of def call_name(a_list:list[Optional[str]]): also into an Option. But like i said at this point i know there are values in my list, so i do not need the Optional any longer.

from typing import Optional
from random import randrange

async def test_me():

    async def call_name(a_list:list[str]):
        '''
        This Function is only fired if the list is populated.
        '''
        for name in a_list:
            print(f"Hello, {name}")

    some_list:list[Optional[str]] = []
    num = randrange(10)

    # SOME PROCESSING
    if 5 >= num:
        # list gets populated
        some_list= ["Ricky", "Joe", "Tyrone"]
    else:
        pass

    if len(some_list) > 0:
        # POINT B
        await call_name(some_list) # <- Type Error

Pylance:

Argument of type "list[str | None]" cannot be assigned to parameter "some_list" of type "list[str]" in function "call_name"
  "list[str | None]" is incompatible with "list[str]"
    Type parameter "_T@list" is invariant, but "str | None" is not the same as "str"
    Consider switching from "list" to "Sequence" which is covariantPylancereportArgumentType