fix: always show schema cache load time

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
```

Author: steve-chavez

src/PostgREST/Logger.hs

@@ -87,9 +87,6 @@ observationLogger loggerState logLevel obs = case obs of
   o@(HasqlPoolObs _) -> do
     when (logLevel >= LogDebug) $ do
       logWithZTime loggerState $ observationMessage o
-  o@(SchemaCacheLoadedObs _) -> do
-    when (logLevel >= LogDebug) $ do
-      logWithZTime loggerState $ observationMessage o
   PoolRequest ->
     pure ()
   PoolRequestFullfilled ->