We weren't resolving a path correctly which resulted in an error on Windows.
For reference, here's the error. Note the extra slash before `C:`:
```
Error: ENOENT: no such file or directory, scandir '/C:/bazel_output_root/yxvwd24o/external/npm/node_modules/typescript'
at Object.readdirSync (fs.js:854:3)
```
PR Close #39005