Remove timescaledb and pg_graphql from supabase template's default extensions

[l2dy]

https://supabase.com/blog/supabase-security-2025-retro:

pg_graphql will be disabled by default on new projects.

https://supabase.com/docs/guides/database/extensions/timescaledb:

The timescaledb extension is deprecated in projects using Postgres 17.

Users can add them as needed, but they should no longer be the default.

[Vonng]

I agree that disabling pg_graphql is a good idea, though I'd prefer to keep the TimescaleDB extensions.

I believe the main reason Supabase dropped it is that, as a DBaaS provider, they cannot run the Timescale TSL version in the cloud. This makes it significantly less useful, as it lacks certain practical features.
However, Pigsty is a self-hosting toolbox, so those restrictions don't apply — it can ship the full TSL version of TimescaleDB. Therefore, it makes sense to:

Remove pg_graphql
Keep TimescaleDB

Having it available out of the box is a significant benefit for users, especially since it's quite complex to enable after the initial bootstrap.