node: fs.existsSync throws when returning false in Node

[bartlomieju]

Describe the bug

Running std/node in Deno:

fs.existsSync("/dev/my-vue-app/vite.config.js/package.json");
Error: Not a directory (os error 20), stat '/dev/my-vue-app/vite.config.js/package.json'

Running in Node:

fs.existsSync("/dev/my-vue-app/vite.config.js/package.json");
false

Expected behavior

Should return false, this is needed for Vite compatibility.

Related #1216
Ref #2055