Allow deno_runtime crate to build in docs.rs

Editor assessment

Allow deno_runtime crate to build in docs.rs states the goal and the constraint in one line: the reader understands that documentation builds were failing and that this enables them. The build type is exactly right and the missing scope is harmless since the crate is named. The change is small and self-explanatory, so the absent body is justified. No footer applies. Clear and publishable. The reader understands both the failure and the goal - docs builds succeeding - which is everything a one-line build fix needs.