community[patch]: update for compatibility with Meilisearch v1.8 (#21979)

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- **Description:** Updates Meilisearch vectorstore for compatibility
with v1.8. Adds [”showRankingScore”:
true”](https://www.meilisearch.com/docs/reference/api/search#ranking-score)
in the search parameters and replaces `_semanticScore` field with `
_rankingScore`


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libs/community/langchain_community/vectorstores/meilisearch.py

@@ -243,6 +243,7 @@ class Meilisearch(VectorStore):
                 "hybrid": {"semanticRatio": 1.0, "embedder": embedder_name},
                 "limit": k,
                 "filter": filter,
+                "showRankingScore": True,
             },
         )
 
@@ -250,7 +251,7 @@ class Meilisearch(VectorStore):
             metadata = result[self._metadata_key]
             if self._text_key in metadata:
                 text = metadata.pop(self._text_key)
-                semantic_score = result["_semanticScore"]
+                semantic_score = result["_rankingScore"]
                 docs.append(
                     (Document(page_content=text, metadata=metadata), semantic_score)
                 )