Remove on-premise Supabase test code

Remove code related to on-premise Supabase testing.

src/lib/supabase/index.ts

@@ -1,19 +1,15 @@
 
 import { supabase, isValidUrl } from './client';
-import { testSupabaseConnection } from './tests';
 import { createRequiredTables, checkTablesStatus } from './setup';
 import { customFetch } from './customFetch';
 import { modifyStorageApiRequest, getStorageApiHeaders } from './storageUtils';
-import { testConnection } from './connectionTest';
 
 export {
   supabase,
   isValidUrl,
-  testSupabaseConnection,
   createRequiredTables,
   checkTablesStatus,
   customFetch,
   modifyStorageApiRequest,
-  getStorageApiHeaders,
-  testConnection
+  getStorageApiHeaders
 };