Remove the dynamic field requirement

What does this MR do and why?

It removes the dynamic requirement of the group_path field in the create member role mutation. The reason is that it creates problems when generating documentation and also in some cases in specs.

There are no changes to behavior. In case the mutation is used on SaaS, the missing group_path will cause an error. Missing group_path is allowed for self-managed.

MR acceptance checklist

Please evaluate this MR against the MR acceptance checklist. It helps you analyze changes to reduce risks in quality, performance, reliability, security, and maintainability.

How to set up and validate locally

Run this mutation on both SaaS (see how to simulate SaaS instance if needed) and self-managed. Check the group_path is required on SaaS but not on self-managed.

mutation {
  memberRoleCreate(input: {
    groupPath: "flightjs"
    name: "Role name", 
    description: "This is a new test role",
    readCode: true,
    readVulnerability: true,
    baseAccessLevel: GUEST
  }) {
    errors
    memberRole {
      id
      name
    }
  }
}