refactor(api/core/workflow/enums.py): Rename SystemVariable to SystemVariableKey. (#7445)

api/core/workflow/enums.py

@@ -1,25 +1,13 @@
 from enum import Enum
 
 
-class SystemVariable(str, Enum):
+class SystemVariableKey(str, Enum):
     """
     System Variables.
     """
-    QUERY = 'query'
-    FILES = 'files'
-    CONVERSATION_ID = 'conversation_id'
-    USER_ID = 'user_id'
-    DIALOGUE_COUNT = 'dialogue_count'
 
-    @classmethod
-    def value_of(cls, value: str):
-        """
-        Get value of given system variable.
-
-        :param value: system variable value
-        :return: system variable
-        """
-        for system_variable in cls:
-            if system_variable.value == value:
-                return system_variable
-        raise ValueError(f'invalid system variable value {value}')
+    QUERY = "query"
+    FILES = "files"
+    CONVERSATION_ID = "conversation_id"
+    USER_ID = "user_id"
+    DIALOGUE_COUNT = "dialogue_count"