fix: refresh from db, remove redundant code

DataCiteApi.mint_public_doi already saves the DOI on the codebase or
codebase release, no need to re-save

Author: alee

django/deploy/cron.daily/doi_mint_pending_releases

@@ -7,4 +7,4 @@
 # Pros of before backups: backups will be more up-to-date
 #
 # currently syncing after backups
-./manage.py doi_mint_pending_releases --no-interactive --no-dry-run
+./manage.py doi_mint_pending_releases --no-interactive --no-dry-run

django/library/doi.py

@@ -556,8 +556,6 @@ def mint_pending_dois(self):
                     (release, log, "Unable to mint DOI for parent codebase")
                 )
                 continue
-            codebase.doi = codebase_doi
-            codebase.save()
 
             """
             Mint DOI for release
@@ -569,15 +567,15 @@ def mint_pending_dois(self):
                     (release, log, "Unable to mint DOI for release")
                 )
                 continue
-            release.doi = log.doi
-            release.save()
 
             logger.debug(
                 "Updating metadata for parent codebase of release %s", release.pk
             )
             """
             Update parent Codebase metadata for new release DOI
             """
+            codebase.refresh_from_db()
+            release.refresh_from_db()
             log, ok = self.update_doi_metadata(codebase)
             if not ok:
                 logger.error("Failed to update metadata for codebase %s", codebase.pk)