Remove Contingent worker value

Summary:

Is there a way to remove contingent worker option from Worker Type

Content (required):

We are looking for a way to hard code the worker type as Employee and make the field read only so that for every requisition created worker type is always Employee and HM/Recruiter cannot change the type.

I have checked the privileges on recruiter role and also checked it on LOV, lookups but did not found the value.

Thus is there a way to either default the employee value in worker type and make it read only

or

remove the contingent worker option.

Version (include the version you are using, if applicable):