support non-result return values in jsg rust

[anonrig]

[github-actions[bot]]

The generated output of @cloudflare/workers-types matches the snapshot in types/generated-snapshot :tada:

[codspeed-hq[bot]]

Merging this PR will not alter performance

Summary

✅ 129 untouched benchmarks
⏩ 49 skipped benchmarks[^skipped]

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_{Comparing yagiz/support-non-result-return-vals (123ae7e) with main (32d43a0)}

[^skipped]: 49 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports.

[anonrig]

Rebased and force pushed.

[anonrig]

Rebased and force pushed.