#4657 Lazy loading: delete compile.ts --no-bundle once a Deno version bump has shipped bundled

swamp-club#4637 made the bundled build the default in scripts/compile.ts and kept --no-bundle as the fallback until one Deno version bump has shipped bundled. After that release, delete the flag and the unbundled path: the bundle default and negatable flag in parseCompileOptions, the main.ts entry branch in compile(), the bundle-dir conditional in restoreBuildState's caller, the parseCompileOptions --no-bundle tests, and the --no-bundle mentions in contributing/startup-benchmarks.md, README.md, scripts/README.md and design/architecture.md. The Deno-upgrade parity step (cli-parity between --no-bundle and the default) then needs another baseline, such as the previous release binary. A build path nobody uses goes stale.