Make chalk/assert shim a Proxy (#15234)

scripts/build/shims/assert.js

@@ -1,4 +1,3 @@
-const assert = () => {};
-assert.ok = assert;
-assert.strictEqual = assert;
+const assert = new Proxy(() => {}, { get: () => assert });
+
 export default assert;

scripts/build/shims/chalk.js

@@ -1,9 +1,3 @@
-const chalk = (x) => x;
-chalk.grey = chalk;
-chalk.red = chalk;
-chalk.bold = chalk;
-chalk.yellow = chalk;
-chalk.blue = chalk;
-chalk.default = chalk;
+const chalk = new Proxy(String, { get: () => chalk });
 
 export default chalk;