[Feature]: Support for pkg.pr.new

[chenjiahan]

What problem does this feature solve?

Add support for https://github.com/stackblitz-labs/pkg.pr.new

This enables users to access features and bug-fixes without the need to wait for release cycles using npm or pull request merges.

What does the proposed API of configuration look like?

Add GitHub actions.

[chenjiahan]

I have Installed the pkg.pr.new GitHub Apps @shulaoda ❤️

[chenjiahan]

We can trigger this action through comments, such as !pkg.pr.new (everyone can trigger it). This can reduce the CI overhead of Rspack repo.

Another approach is to trigger it only in the main branch, @hardfist what do you think