feat(tests): add EIP-2780 coverage gap tests

[spencer-tb]

Description

Rebase of #3296 now that #3266 has merged. Adds three EIP-2780 coverage gaps, all filled green:

• test_intrinsic_gas_floor_boundary_all_tx_types: the intrinsic - 1 rejection boundary for every transaction type (previously only types 0 and 4 had one).
• test_setcode_tx_across_amsterdam_transition: a type-4 transaction straddling the fork boundary, pinning the per-authorization cost migrating from the pre-fork intrinsic (AUTH_PER_EMPTY_ACCOUNT) into the decomposed intrinsic plus top-frame charges, cross-checked against a hand-derived per-fork decomposition.
• test_calldata_floor_with_authorizations: a binding calldata floor on a type-4 transaction, pinning that authorization tuples add no floor tokens while the masked delegation still lands, and that one gas below the floor rejects.

Related Issues or PRs

Supersedes #3296; part of the EIP-2780 coverage item in #3217.

Checklist

• Ran fast static checks to avoid CI fails, see Code Standards & Verifying Changes: just static
• PR title has the form <type>(<area>): <title>, where <type> and <area> come from an appropriate C-<type>, respectively A-<area>, label. The title should match the target squash commit message.

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 93.50%. Comparing base (f1aa970) to head (93f6d78).
⚠️ Report is 3 commits behind head on forks/amsterdam.

Additional details and impacted files

@@               Coverage Diff                @@
##           forks/amsterdam    #3318   +/-   ##
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  Coverage            93.50%   93.50%           
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  Files                  624      624           
  Lines                37070    37070           
  Branches              3394     3394           
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  Hits                 34661    34661           
  Misses                1653     1653           
  Partials               756      756           

Flag	Coverage Δ
unittests	93.50% <ø> (ø)

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[spencer-tb]

Forwarding from previous review via @marioevz: (LouisTsai-Csie#16)

[LouisTsai-Csie]

LGTM, only leave a comment on the docstrings:

we should simplify them if the test or function already clearly expresses its intent.
I've noticed docstrings getting longer in the repo, which creates maintenance overhead. When tests or functions change, we'll need to update the documentation too, which becomes kind of review burden. What do you think?

[spencer-tb]

Thx @LouisTsai-Csie! Addressed!