PERF: isin casting integers to object (#38346)

Author: jbrockmendel

pandas/core/algorithms.py

@@ -440,8 +440,7 @@ def isin(comps: AnyArrayLike, values: AnyArrayLike) -> np.ndarray:
     if not isinstance(
         values, (ABCIndexClass, ABCSeries, ABCExtensionArray, np.ndarray)
     ):
-        values = construct_1d_object_array_from_listlike(list(values))
-        # TODO: could use ensure_arraylike here
+        values = _ensure_arraylike(list(values))
     elif isinstance(values, ABCMultiIndex):
         # Avoid raising in extract_array
         values = np.array(values)