sql/rls: rolbypassrls in pg_roles is always false

[spilchen]

The vtable pg_roles currently always fills in false for the column rolbypassrls. Now that we have implemented the BYPASSRLS role option, we can properly fill in this column now.

root@127.0.0.1:26257/demoapp/movr> create role can_bypassrls with bypassrls;
CREATE ROLE

Time: 58ms total (execution 58ms / network 0ms)

root@127.0.0.1:26257/demoapp/movr> SELECT rolbypassrls from pg_roles where rolname = 'can_bypassrls';
  rolbypassrls
----------------
       f
(1 row)

Time: 6ms total (execution 5ms / network 0ms)

Jira issue: CRDB-50438

Epic CRDB-48807

[spilchen]

When we fix this, we should include a release note in the commit so that we will remember to update the docs as this was originally intended to be a way to find all roles that bypass RLS.