Change default `publicDir` in `build` JavaScript API

[userquin]

Description

When using build programatically, publicDir is enabled by default, that's, publicDir will be applied.

I was talking with @patak-dev about this.

Suggested solution

Split build adding a new variant or change the default publicDir to false.

Alternative

None: I'm preparing a PR to add a warning in the docs.

Additional context

For single builds there is no problem but using build in secondary build processes (meta frameworks or Vite plugins) can lead in unexpected side effects, for example:

• fix: don't copy public folder when building custom sw vite-pwa/vite-plugin-pwa#525
• fix: don't copy public folder in service worker build sveltejs/kit#10082
• fix(pwa): pwa icons in dev and build elk-zone/elk#2137

In elk.zone repo, all public Nuxt 3 build assets were being overwritten after service worker build.

Validations

• Follow our Code of Conduct
• Read the Contributing Guidelines.
• Read the docs.
• Check that there isn't already an issue that request the same feature to avoid creating a duplicate.