Timeout Google Cloud Memorystore Redis over TLS (`rediss://`) on port 6378

[putradpangestu]

Bug Report
Version
svix-server 1.67

Platform
GKE GCP

Description
My issue is: when using Google Cloud Memory Store for Redis, which uses TLS, it automatically exposes port x.x.x.x:6378.

When using:
SVIX_REDIS_DSN : rediss://:abc@x.x.x.x:6378/0?ssl_cert_reqs=none
or:
SVIX_REDIS_DSN : rediss://:abc@x.x.x.x:6378/0

Svix always times out.

Logs:

+ WAIT_FOR_ARG=--wait-for 15
+ exec svix-server --run-migrations --wait-for 15
thread 'main' panicked at /app/svix-server/src/queue/redis.rs:152:14:
Error retrieving connection from Redis pool: TimedOut
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

Connectivity to the instance is confirmed: redis-cli --tls --insecure works from the same container.
Expected behavior:

Svix should be able to connect to GCP Memory Store Redis TLS endpoint on port 6378.

Actual behavior:
Svix panics due to TimedOut retrieving connection from Redis pool.
This blocks usage of GCP Memorystore (TLS mode) with Svix without adding a TLS sidecar/proxy workaround.