fix: build step

This proposal has been merged to the ECMAScript standard and thus this
plugin is no longer maintained. We should use
@babel/plugin-transform-object-rest-spread instead.

config/babel.config.js

@@ -14,7 +14,7 @@ module.exports = {
     '@babel/plugin-transform-runtime',
     '@babel/plugin-syntax-dynamic-import',
     '@babel/plugin-proposal-class-properties',
-    '@babel/plugin-proposal-object-rest-spread',
+    '@babel/plugin-transform-object-rest-spread',
     '@babel/plugin-proposal-optional-chaining',
   ],
 }