Defer source map deletion until Nuxt's `close` hook, after Nitro has
copied public assets into the final output directory.

## Root cause

The Vite plugin previously deleted source maps from Nuxt's intermediate
client build output. Nitro subsequently copied those assets into the
final output, causing the source maps to reappear.

The Vite and Rollup plugins continue to inject debug IDs and upload
source maps, but receive options with deletion disabled. Once the
complete Nuxt build finishes, the Nuxt integration uses the bundler
plugin manager to delete artifacts.

Backport of #23407 to v10. On v10 the Nuxt SDK still uses the published
`@sentry/vite-plugin`/`@sentry/rollup-plugin` v5 packages rather than the
in-repo `@sentry/bundler-plugins`, so the build plugin manager is taken
from `@sentry/bundler-plugin-core` — the same v5 core those plugins are
built on, and the one `@sentry/nextjs` and `@sentry/nitro` already use.

Closes #22801

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>