Update Supabase version and improve Keystatic's configurations

This commit updates the version of Supabase in multiple packages. It also introduces specificity to environment variables in Keystatic configuration and adds a method to create a 'KeyStatic' reader based on the storage kind. Furthermore, minor adjustments have been made to keep the environment variable names consistent.

packages/cms/keystatic/src/keystatic-route-handler.tsx

@@ -1,7 +1,7 @@
 import { makeRouteHandler } from '@keystatic/next/route-handler';
 
-import keystaticConfig from './keystatic.config';
+import config from './keystatic.config';
 
 export const { POST, GET } = makeRouteHandler({
-  config: keystaticConfig,
+  config,
 });