Tokens service's readiness check depends on PG

As a lesson for a previous incident we had, we verified the dependencies of the `tokens` service and realized it depends on PG to run, while it doesn't have to. This might lead to a restart/failure of tokens service in case of a PG incident/downtime.

The tokens service is capable of running only with Redis/local cache, and it doesn't have to depend on PG in the readiness/health check.

https://github.com/graphql-hive/console/blob/main/packages/services/tokens/src/index.ts#L165