fix: backup trimming, only selecting zstd file (#846)

backup/pvc/bin/run.sh

@@ -11,6 +11,6 @@ do
     if [[ ! -z "${BACKUP_COUNT}" ]]; then
         echo "Trimming to only ${BACKUP_COUNT} recent backups in preparation for new backup"
         #TODO: add the list of exceeding backup before delete
-        find ${BACKUP_DIR} -maxdepth 1 -name '*.tar.*' -exec basename {} \; | sort -gr | tail -n +$((BACKUP_COUNT +1)) | xargs -I '{}' rm ${BACKUP_DIR}/'{}'
+        find ${BACKUP_DIR} -maxdepth 1 -name '*.tar.zstd' -exec basename {} \; | sort -gr | tail -n +$((BACKUP_COUNT +1)) | xargs -I '{}' rm ${BACKUP_DIR}/'{}'
     fi
 done