chore: replace error by proper typing

Author: Ludovic CHAPELET

src/pytest_bdd/parser.py

@@ -233,12 +233,12 @@ def render(self, context: Mapping[str, object]) -> Scenario:
             rule=self.rule,
         )
 
-    def find_scenario_example_from_context(self, context: Mapping[str, object]) -> Examples:
+    def find_scenario_example_from_context(self, context: Mapping[str, object]) -> Examples | None:
         for example in self.examples:
             example_param = dict(zip(example.example_params, example.examples[0]))
             if example_param == context:
                 return example
-        raise ValueError("No matching example found for the given context.")
+        return None
 
 
 @dataclass(eq=False)