fix: correct Azure AI search _in delimiter (#1729)

* correct _in delimiter

* update spacing

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Co-authored-by: Amna Mubashar <amnahkhan.ak@gmail.com>

Author: sggerard

integrations/azure_ai_search/src/haystack_integrations/document_stores/azure_ai_search/filters.py

@@ -79,8 +79,8 @@ def _in(field: str, value: Any) -> str:
     if not isinstance(value, list) or any(not isinstance(v, str) for v in value):
         msg = "Azure AI Search only supports a list of strings for 'in' comparators"
         raise AzureAISearchDocumentStoreFilterError(msg)
-    values = ", ".join(map(str, value))
-    return f"search.in({field},'{values}')"
+    values = ",".join(map(str, value))
+    return f"search.in({field},'{values}',',')"
 
 
 def _comparison_operator(field: str, value: Any, operator: str) -> str: