Fix: remove dead copy_context() call in run_with

copy_context() was assigned but never used — ctx.run() does not work
for async functions (it returns a coroutine without executing the body).
The token-based _settings.set()/_settings.reset(tok) pattern is already
re-entrant safe, and asyncio Task-per-request isolation covers the ASGI
deployment. No behavioral change.

Closes #91

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: aniket-s-kulkarni

src/dremioai/config/settings.py

@@ -48,7 +48,7 @@
 from functools import reduce
 from operator import ior
 from shutil import which
-from contextvars import ContextVar, copy_context
+from contextvars import ContextVar
 from os import environ
 from importlib.util import find_spec
 from datetime import datetime
@@ -578,7 +578,6 @@ async def _call():
         finally:
             _settings.reset(tok)
 
-    ctx = copy_context()
     return await _call()