fix: Show number of loaded timezones in log output

There is no reason to hide those, right?

src/PostgREST/SchemaCache.hs

@@ -95,13 +95,14 @@ instance JSON.ToJSON SchemaCache where
     ]
 
 showSummary :: SchemaCache -> Text
-showSummary (SchemaCache tbls rels routs reps mediaHdlrs _) =
+showSummary (SchemaCache tbls rels routs reps mediaHdlrs tzs) =
   T.intercalate ", "
   [ show (HM.size tbls)       <> " Relations"
   , show (HM.size rels)       <> " Relationships"
   , show (HM.size routs)      <> " Functions"
   , show (HM.size reps)       <> " Domain Representations"
   , show (HM.size mediaHdlrs) <> " Media Type Handlers"
+  , show (S.size tzs)         <> " Timezones"
   ]
 
 -- | A view foreign key or primary key dependency detected on its source table