util: Remove redundant cast in run_curl_into

The cast to 'T' in run_curl_into was redundant: mypy already narrows
the return value of json.loads() to type T after the isinstance(ret,
expected_type) check (where expected_type: type[T]).

Remove the unnecessary cast and clean up the unused 'cast' import.
This satisfies the new warn_redundant_casts mypy rule.

Assisted-by: unsloth/Qwen3.6-35B-A3B-GGUF:IQ4_NL and pi.dev 0.81.1
Signed-off-by: Jan Lindemann <jan@janware.com>

src/python/jw/pkg/lib/util.py

@@ -5,7 +5,7 @@ import os
 import sys
 
 from enum import Enum, auto
-from typing import TYPE_CHECKING, Iterable, TypeVar, cast
+from typing import TYPE_CHECKING, Iterable, TypeVar
 
 from .base import Input, InputMode, Result
 from .log import DEBUG, ERR, log
@@ -93,7 +93,7 @@ async def run_curl_into(
         raise TypeError(
             f'Expected {expected_type.__name__}, got {type(ret).__name__} from Curl'
         )
-    return cast('T', ret)
+    return ret
 
 async def run_askpass(
     askpass_env: list[str],