chore(ci): resolve redis port conflicts for redis-auth

[windmgc]

Summary

This PR changes the listen port of redis-auth to 6385.

• The redis-auth instance actually listens on 6379 but a wrong port(6381) was mapped to the host(only for local development), so if you connect to the mapping port for redis-auth after start_service it will throw out the error Error: Server closed the connection. Workflow CI does not have such issue, the correct port was mapped
• Change the listen port to 6385, this is actually benefit for ee repo since we already have a sentinel's replica listening on port 6381(see here https://github.com/Kong/kong-ee/blob/227e0b20999279c86b9203203fa758922b63e6ee/spec/fixtures/redis_sentinel/redis-sentinel-compose.yaml#L22)