Fix bandit security warnings

Add nosec comment for intentional try/except/continue pattern in schema detection

Author: abrookins

aredis_om/model/migrations/datetime_migration.py

@@ -54,7 +54,7 @@ async def check_for_schema_mismatches(self, models: List[Any]) -> Dict[str, Any]
                     # Try to get index info
                     index_info = await self.redis.execute_command("FT.INFO", index_name)
                     current_schema = self._parse_index_schema(index_info)
-                except Exception:
+                except Exception:  # nosec B112
                     # Index doesn't exist or other error - skip this model
                     continue