Escape paths in npm.sh to fix #20907

[ghost]

I had cloned vscode into a folder within iCloud Drive ~/Library/Mobile Documents/com~apple~CloudDocs/vscode and on ./scripts/npm.sh i I was getting:

usage: dirname path
usage: dirname path
cat: /package.json: No such file or directory

This pull request adds escaping (not tested on Linux). Closes #20907.

[mention-bot]

@flagello, thanks for your PR! By analyzing the history of the files in this pull request, we identified @egamma and @bpasero to be potential reviewers.

[msftclas]

Hi @flagello, I'm your friendly neighborhood Microsoft Pull Request Bot (You can call me MSBOT). Thanks for your contribution!

This seems like a small (but important) contribution, so no Contribution License Agreement is required at this point. Real humans will now evaluate your PR.

TTYL, MSBOT;

[ghost]

Closed by error while cleaning up

[msftclas]

This seems like a small (but important) contribution, so no Contribution License Agreement is required at this point. We will now review your pull request.
Thanks,
Microsoft Pull Request Bot

[joaomoreno]

Thanks!