Revert "[keyserver][lib] don't generate one time keys on identity login"

Summary:
This reverts commit d2f01b572f830ac56514bc6557ef3c1c20379787.

Depends on D13575

Resolves https://linear.app/comm/issue/ENG-9440/clients-should-include-otks-on-first-login

Test Plan: set up a new keyserver with my test user credentials, on login my keyserver's OTKs were present in DynamoDB

Reviewers: will, bartek, ashoat

Reviewed By: ashoat

Subscribers: ashoat, tomek

Differential Revision: https://phab.comm.dev/D13577