Use str, Enum to achieve what StrEnum does so that we are compatible …

…with older versions of Python.

.github/workflows/testing_ci.yml

@@ -11,7 +11,6 @@ permissions:
 
 jobs:
   build:
-
     runs-on: ubuntu-latest
 
     steps:

testing/invariant/custom_types/matchers.py

@@ -1,6 +1,6 @@
 """Defines the expect functions."""
 
-from enum import StrEnum
+from enum import Enum
 from typing import Any
 
 from invariant.scorers.llm.classifier import Classifier
@@ -86,7 +86,7 @@ def matches(self, actual_value: str):
 class IsFactuallyEqual(Matcher):
     """Matcher for checking if the output is close to expected using llm."""
 
-    class Agreement(StrEnum):
+    class Agreement(str, Enum):
         """Enum for different levels of agreement."""
 
         SUPER_STRICT_AGREEMENT = "super strict agreement"

testing/invariant/scorers/llm/clients/client.py

@@ -1,11 +1,11 @@
 """Abstract base class for LLM clients."""
 
 from abc import ABC, abstractmethod
-from enum import StrEnum
+from enum import Enum
 from typing import Any
 
 
-class SupportedClients(StrEnum):
+class SupportedClients(str, Enum):
     """Enumeration of supported LLM clients."""
 
     OPENAI = "OpenAI"