AFAIK there is not OOTB feature.
We can disable notifications but not sure about disabling it workflow specific. I would let others also share their thoughts here.
For disabling default email notifications:
1. Go to /system/console/configMgr Eg: http://<hostname>:<port>/system/console/configMgr
2. Edit the configuration called 'Day CQ workflow Email Notification Service'
3. Disable 'Notify on Abort' and 'Notify on Complete' options.
~kautuk