SQL tenants must not use RESTORE/IMPORT. This is because it won't work (without extra engineering work not slated for phase 2) but also because we can't have SQL tenants make arbitrary connections to the outside world.
Additionally, IMPORT INTO uses protected timestamps which won't be available.

All import/restore related functionality ought to be disabled for SQL tenant servers.

Should wait for #47903 to close.

Jira issue: CRDB-4377