`operation not permitted, unlink` during `Cleaning npm cache`: missing `/` ?

This was reported by a user:

```
Cleaning npm cache...
Spawning child process "npm cache clean --force" with pid=10588
npm WARN using --force Recommended protections disabled.
npm ERR! code EPERM
npm ERR! syscall unlink
npm ERR! path C:\Users\NATURE\AppData\Local\npm-cache_cacache\tmp\78d73d42
npm ERR! errno -4048
npm ERR! Error: EPERM: operation not permitted, unlink 'C:\Users\NATURE\AppData\Local\npm-cache_cacache\tmp\78d73d42'
npm ERR! [Error: EPERM: operation not permitted, unlink 'C:\Users\NATURE\AppData\Local\npm-cache_cacache\tmp\78d73d42'] {
npm ERR! errno: -4048,
npm ERR! code: 'EPERM',
npm ERR! syscall: 'unlink',
npm ERR! path: 'C:\Users\NATURE\AppData\Local\npm-cache\_cacache\tmp\78d73d42'
npm ERR! }
npm ERR!
npm ERR! The operation was rejected by your operating system.
npm ERR! It's possible that the file was already in use (by a text editor or antivirus),
npm ERR! or that you lack permissions to access it.
```