(fix): do not allow concurrent cronjobs

minds-cronjobs/values.yaml

@@ -2,7 +2,7 @@ imageRepository: registry.gitlab.com/minds/engine/runners
 imageTag: production
 imagePullPolicy: Always
 
-concurrencyPolicy: Allow
+concurrencyPolicy: Forbid
 restartPolicy: OnFailure
 failedJobsHistoryLimit: 3
 successfulJobsHistoryLimit: 1
@@ -113,4 +113,4 @@ jobs:
     schedule: "30 1 * * *"
     args:
       - "-c"
-      - "php /var/www/Minds/engine/cli.php rewards sync"
\ No newline at end of file
+      - "php /var/www/Minds/engine/cli.php rewards sync"