chore: remove old prompt object (#1535)

Author: jjmachan

src/ragas/llms/base.py

@@ -20,10 +20,9 @@
 
 if t.TYPE_CHECKING:
     from langchain_core.callbacks import Callbacks
+    from langchain_core.prompt_values import PromptValue
     from llama_index.core.base.llms.base import BaseLLM
 
-    from ragas.llms.prompt import PromptValue
-
 logger = logging.getLogger(__name__)
 
 MULTIPLE_COMPLETION_SUPPORTED = [