Nit: use plain setattr in strip_disabled_fields

The previous object.__setattr__ was defensive bypass-validation, but every
field in DISABLED_SAMPLING_PARAMS is declared as `<type> | None = None` on the
underlying langchain subclasses, so None is always valid. `strip_disabled_fields`
runs inside `@model_validator(mode="after")` and operates on the constructed
pydantic model, so plain setattr already goes through `BaseModel.__setattr__`
and respects field types. If a future caller tries to disable a non-nullable
custom field, raising is the right behavior — better than silently bypassing.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: cosminacho

src/uipath/llm_client/utils/sampling.py

@@ -132,6 +132,4 @@ def strip_disabled_fields(
                     current,
                     model_name,
                 )
-            # object.__setattr__ bypasses pydantic field validation in case the
-            # field's declared type forbids None.
-            object.__setattr__(instance, key, None)
+            setattr(instance, key, None)