Degree attestation from Pakistan Embassy Riyadh

As far as I know, Pakistan Embassy will not attest any Pakistan issued degree without attestation from MOFA Pakistan.   Because their attestation is to verify stamp of MOFA Pakistan. 

You can try your luck but this is clearly listed under requirements on the Pakistan Embassy KSA website :

https://pakistaninksa.com/educational-document/

And if you are doing this to use the degree in Saudi, even with Pakistan Embassy stamp, Jawazat will still ask for stamp from Saudi Culture (Even if you do the short cut of getting MOFA Saudi attestation on Pak Embassy stamp).   So logically speaking, the route is MOFA Pakistan to Saudi Culture to Saudi Embassy in Pakistan.  After that MOFA Saudi attestation which is easy.   You won't need anything from Pakistan Embassy in that case.

Pakistan Embassy attestation is only beneficial in one circumstance (if your degree is MOFA Pakistan attested).  Assume you are moving to UAE and don't want to do the whole verification process again from Pakistan.  In this case, you get degree stamped from Pak Embassy and then Saudi MOFA (MOFA verifies stamp of Pak Embassy) followed by UAE Embassy in Saudi (who verify stamp of MOFA Saudi).  Now you can proceed straight to UAE.