[native][web] remove unused device ID code

Summary: this is a follow up (depends on D9556). we don't need any of this device ID code now that we're just using the content ed25519 public key as the device ID.

Test Plan: successfully built and ran native and web

Reviewers: kamil, inka

Reviewed By: kamil, inka

Subscribers: inka, ashoat, tomek, wyilio

Differential Revision: https://phab.comm.dev/D9612