[update-product-data] Don't fail when date is formatted as string

Currently update-product-data produces YAML with dates as string for unlisted releases. This may be an issue when running again the script after having copy-pasted the produced YAML. This fixes this issue.

update-product-data.py

@@ -66,6 +66,9 @@ class ReleaseCycle:
 
     def __update_release_date(self, date: datetime.date) -> None:
         release_date = self.data.get("releaseDate", None)
+        if isinstance(release_date, str):
+            release_date = datetime.date.fromisoformat(release_date)
+
         if release_date and release_date > date:
             logging.info(f"{self} releaseDate updated from {release_date} to {date} using version data")
             self.data["releaseDate"] = date