fix: migrate to standard import attributes (#8803)

packages/backend/server/src/fundamentals/config/default.ts

@@ -1,7 +1,7 @@
 import { resolve } from 'node:path';
 import { fileURLToPath } from 'node:url';
 
-import pkg from '../../../package.json' assert { type: 'json' };
+import pkg from '../../../package.json' with { type: 'json' };
 import {
   AFFINE_ENV,
   AFFiNEConfig,