fix: eth: handle a potential divide by zero in receipt handling

[Stebalien]

Related Issues

fixes #10471

Proposed Changes

This isn't really possible to hit on-chain at this piont (message won't be accepted) but we might as well be extra careful.

Checklist

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• Commits have a clear commit message.
• PR title is in the form of of <PR type>: <area>: <change being made>
  • example: fix: mempool: Introduce a cache for valid signatures
  • PR type: fix, feat, build, chore, ci, docs, perf, refactor, revert, style, test
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• Tests exist for new functionality or change in behavior
  • Kind of annoying to test as lotus will reject the message.
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