chore: ci: build `Linux release` on a hosted runner at release level

Sends the stamped `Linux release` build to the hosted runner even when the self-hosted one is free, so that every artifact we ship is produced on the same class of machine. The self-hosted runner carries a different toolset: it has no Rust, which `Build nanoda` needs, while every hosted runner has it.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01JPPJuXrRxwXgsWEAqM62dd