[lib] Remove convertClientToServerInfos from spec
Summary:
Part of ENG-4959
Depends on D9328
convertClientToServerInfos stopped being used after changes in D9328.
Test Plan: yarn flow-all
Reviewers: tomek, inka, kamil
Reviewed By: tomek
Subscribers: ashoat
Differential Revision: https://phab.comm.dev/D9329