Ensure the reference id is always a string

Signed-off-by: Keshav Priyadarshi <git@keshav.space>

Author: keshav-space

vulnerabilities/importer.py

@@ -125,7 +125,7 @@ def to_dict(self):
     @classmethod
     def from_dict(cls, ref: dict):
         return cls(
-            reference_id=ref["reference_id"],
+            reference_id=str(ref["reference_id"]),
             reference_type=ref.get("reference_type") or "",
             url=ref["url"],
             severities=[