feat(tests): Add worst-case SSTORE test

[nerolation]

🗒️ Description

Add test_sstore_bloated_multi_contract: SSTORE benchmark spreading writes across many fresh contracts and stride-spaced (2**240) slots within each, while a shared dependency_holder enforces an inter-tx RAW edge. Maximizes MPT breadth at post-state-root computation while keeping txs serialized.

🔗 Related Issues or PRs

N/A.

✅ Checklist

• All: Ran fast static checks to avoid unnecessary CI fails, see also Code Standards and Enabling Pre-commit Checks: just static
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Cute Animal Picture

TBD

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 88.17%. Comparing base (8d8301c) to head (eb5f4bc).

Additional details and impacted files

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##           forks/amsterdam    #2757   +/-   ##
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  Coverage            88.17%   88.17%           
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  Files                  577      577           
  Lines                35659    35659           
  Branches              3490     3490           
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  Hits                 31442    31442           
  Misses                3654     3654           
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Flag	Coverage Δ
unittests	88.17% <ø> (ø)

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[LouisTsai-Csie]

Looks good from my side!

[nerolation]

One issue with this test is that the contracts I'm targeting have no storage. I talked with @CPerezz and @jochem-brouwer about this but essentially we need to first deploy the needed code to some accounts (while keeping track of them), then bloating the storage slots (while keeping track of them) and then selecting accounts + storage slots that are far from each other such that the post-state root calculation becomes "worst-case".
Each transaction targets a different contract and within those contracts the tx targets distinct storage slots far from each other. The result would be worst-case root calc times for each individual account AND worst-case state root calculation over the accounts.

[LouisTsai-Csie]

@nerolation I’m not sure I fully understand your comment, and I’d like to know the next steps:

• Do you need additional bloating on perf-devnet-3? If so, Jochem and Carlos can help with that.
• Would you prefer that I merge this PR first and then open a new one for future refactor? Or keep this PR open and not merge it?

For information, I recently merged a PR (#2672) that addresses the initcode prefix length issue. If that’s the current bottleneck, it might be worth taking a look at this benchmark.