langchain[small]: Change type to BasePromptTemplate (#23083)

```python
Change from_llm(
 prompt: PromptTemplate 
 ...
 )
```
 to
```python
Change from_llm(
 prompt: BasePromptTemplate 
 ...
 )
```

libs/langchain/langchain/retrievers/multi_query.py

@@ -9,6 +9,7 @@ from langchain_core.callbacks import (
 from langchain_core.documents import Document
 from langchain_core.language_models import BaseLanguageModel
 from langchain_core.output_parsers import BaseOutputParser
+from langchain_core.prompts import BasePromptTemplate
 from langchain_core.prompts.prompt import PromptTemplate
 from langchain_core.retrievers import BaseRetriever
 from langchain_core.runnables import Runnable
@@ -62,7 +63,7 @@ class MultiQueryRetriever(BaseRetriever):
         cls,
         retriever: BaseRetriever,
         llm: BaseLanguageModel,
-        prompt: PromptTemplate = DEFAULT_QUERY_PROMPT,
+        prompt: BasePromptTemplate = DEFAULT_QUERY_PROMPT,
         parser_key: Optional[str] = None,
         include_original: bool = False,
     ) -> "MultiQueryRetriever":

libs/langchain/langchain/retrievers/re_phraser.py

@@ -7,6 +7,7 @@ from langchain_core.callbacks import (
 )
 from langchain_core.documents import Document
 from langchain_core.language_models import BaseLLM
+from langchain_core.prompts import BasePromptTemplate
 from langchain_core.prompts.prompt import PromptTemplate
 from langchain_core.retrievers import BaseRetriever
 
@@ -36,7 +37,7 @@ class RePhraseQueryRetriever(BaseRetriever):
         cls,
         retriever: BaseRetriever,
         llm: BaseLLM,
-        prompt: PromptTemplate = DEFAULT_QUERY_PROMPT,
+        prompt: BasePromptTemplate = DEFAULT_QUERY_PROMPT,
     ) -> "RePhraseQueryRetriever":
         """Initialize from llm using default template.