fix(py/plugins/evaluators): fix strenum imports (#3944)

Author: yesudeep

py/plugins/evaluators/pyproject.toml

@@ -30,7 +30,12 @@ classifiers = [
   "Topic :: Scientific/Engineering :: Artificial Intelligence",
   "Topic :: Software Development :: Libraries",
 ]
-dependencies = ["genkit", "jsonata-python>=0.5.3", "pydantic>=2.10.5"]
+dependencies = [
+    "genkit",
+    "jsonata-python>=0.5.3",
+    "pydantic>=2.10.5",
+    "strenum>=0.4.15; python_version < '3.11'",
+]
 description = "Genkit Evaluators Plugin for RAGAS"
 license = { text = "Apache-2.0" }
 name = "genkit-plugin-evaluators"

py/plugins/evaluators/src/genkit/plugins/evaluators/constant.py

@@ -16,7 +16,10 @@
 
 
 from collections.abc import Callable
-from enum import StrEnum
+try:
+    from enum import StrEnum
+except ImportError:
+    from strenum import StrEnum
 from typing import Any
 
 from pydantic import BaseModel, RootModel