Update the URL of npm mirror

Created by: LinuxSuRen

What type of PR is this?

/kind cleanup

What this PR does / why we need it:

The NPM mirror address has changed. It changed from 'registry.npm.taobao.org' to 'registry.npmmirror.com'.

See also this article.

Which issue(s) this PR fixes:

Fixes #

Special notes for reviewers:

None

Does this PR introduced a user-facing change?

None

Additional documentation, usage docs, etc.:

None