chore(mistral): remove invalid no cover

Remove invalid no cover comment from Mistral model flagged by
strict-no-cover check.

Author: stevenh

pydantic_ai_slim/pydantic_ai/models/mistral.py

@@ -423,7 +423,7 @@ def _get_python_type(cls, value: dict[str, Any]) -> str:
         if value_type == 'object':
             additional_properties = value.get('additionalProperties', {})
             if isinstance(additional_properties, bool):
-                return 'bool'  # pragma: no cover
+                return 'bool'
             additional_properties_type = additional_properties.get('type')
             if (
                 additional_properties_type in SIMPLE_JSON_TYPE_MAPPING