Add api tests for deleting link password

[SwikritiT]

Test scenarios to add

• only Admin and Space Admin can remove the password in read-only public link [full-ci] add new permission to delete public link password #7540
• all users can remove their password if set the permission 0 (invite people) [tests-only][full-ci]tests: add tests for update public link to delete password (permission 0) #7894

Related Bugs

• Normal users can update the public link to delete its password if permission is not sent in data #7821

[SagarGi]

Related PRs for the test coverage has been merged. So closing this issue.