chore(internal): add lru_cache helper function (openai#1329)

Author: stainless-bot

Diff for: src/openai/_utils/__init__.py

@@ -6,6 +6,7 @@
     is_list as is_list,
     is_given as is_given,
     is_tuple as is_tuple,
+    lru_cache as lru_cache,
     is_mapping as is_mapping,
     is_tuple_t as is_tuple_t,
     parse_date as parse_date,

Diff for: src/openai/_utils/_utils.py

@@ -389,3 +389,11 @@ def get_async_library() -> str:
         return sniffio.current_async_library()
     except Exception:
         return "false"
+
+
+def lru_cache(*, maxsize: int | None = 128) -> Callable[[CallableT], CallableT]:
+    """A version of functools.lru_cache that retains the type signature
+    for the wrapped function arguments.
+    """
+    wrapper = functools.lru_cache(maxsize=maxsize)
+    return cast(Any, wrapper)  # type: ignore[no-any-return]