* ensure final dot on node name
This ensures that nodes which have a base domain set, will have a dot appended to their FQDN.
Resolves: https://github.com/juanfont/headscale/issues/2501
* improve OIDC TTL expire test
Waiting a bit more than the TTL of the OIDC token seems to remove some flakiness of this test. This furthermore makes use of a go func safe buffer which should avoid race conditions.