Don't restrict nitro/nuxt3 runtime components

Editor assessment

The subject states the relaxation precisely — nitro and nuxt3 runtime components are no longer restricted — so the header communicates the fix and the previously blocked case without the diff, and fix(nuxt3) classifies and locates it correctly. Hygiene is clean: imperative mood, no trailing period, sensible length, no ticket junk. No body is needed for a contained allowlist fix, and no footer is required. A line on the errors users hit when importing runtime components would add depth; the message is already clear, accurate, and publishable.