It used to be that this was only enabled with log-level=debug.
But the default log-level is misleading, for example:
```
$ PGRST_DB_SCHEMAS="apflora" postgrest-with-postgresql-16 -f test/io/big_schema.sql postgrest-run
...
13/Nov/2024:22:08:20 -0500: Config reloaded
13/Nov/2024:22:08:20 -0500: Schema cache queried in 36.3 milliseconds
13/Nov/2024:22:08:20 -0500: Schema cache loaded 326 Relations, 305 Relationships, 7 Functions, 0 Domain Representations, 4 Media Type Handlers, 1194 Timezones
```
The "Schema cache loaded" can take a while to appear, yet the 22:08:20
time is the same. If we reveal the load time this is clarified:
```
13/Nov/2024:22:08:37 -0500: Schema cache loaded in 16770.1 milliseconds
```
With this:
- Is no longer necessary to pass observer as an argument
to every function that needs observations.
- We can invoke the observer on every function that uses AppConfig.
However it'd be better to just call the observer in the upper modules
(like on App.hs).
