Fixed pages having leading/trailing whitespace, with test

Author: jamesbraza

paperqa/types.py

@@ -618,7 +618,7 @@ def merge_bibtex_entries(entry1: Entry, entry2: Entry) -> Entry:
     def misc_string_cleaning(data: dict[str, Any]) -> dict[str, Any]:
         """Clean strings before the enter the validation process."""
         if pages := data.get("pages"):
-            data["pages"] = pages.replace("--", "-").replace(" ", "")
+            data["pages"] = pages.replace("--", "-").replace(" ", "").strip()
         return data
 
     @staticmethod