refactor(core): don't use deprecated input_variables param in from_file (#33104)

Missed awhile back; causes warnings during tests

Author: mdrxy

libs/core/langchain_core/prompts/chat.py

@@ -262,7 +262,7 @@ def from_template(
     def from_template_file(
         cls,
         template_file: Union[str, Path],
-        input_variables: list[str],
+        input_variables: list[str],  # noqa: ARG003  # Deprecated
         **kwargs: Any,
     ) -> Self:
         """Create a class from a template file.
@@ -275,7 +275,7 @@ def from_template_file(
         Returns:
             A new instance of this class.
         """
-        prompt = PromptTemplate.from_file(template_file, input_variables)
+        prompt = PromptTemplate.from_file(template_file)
         return cls(prompt=prompt, **kwargs)
 
     @abstractmethod