fix: remove slots=True for Python 3.9 compatibility

dataclass(slots=True) requires Python 3.10+.

Author: KRRT7

codeflash/optimization/parallel_evaluator.py

@@ -28,15 +28,15 @@
     )
 
 
-@dataclasses.dataclass(slots=True)
+@dataclasses.dataclass
 class EvalFailure:
     """Structured failure from parallel evaluation, carrying test diffs for repair."""
 
     message: str
     diffs: list[TestDiff] = dataclasses.field(default_factory=list)
 
 
-@dataclasses.dataclass(slots=True)
+@dataclasses.dataclass
 class _BehavioralPass:
     """Intermediate result: candidate passed behavioral tests, ready for benchmarking."""