feat(spec-specs, tests): EIP-8037 drop double refund on incorporate_child_on_error

[spencer-tb]

🗒️ Description

Drops the state_gas_refund subtract in incorporate_child_on_error. The subtract over-billed the user by the refunded amount on any failure boundary that contained an inline credit (SSTORE 0→x→0 or CREATE silent failure), in both same-frame and cross-frame variants. With the subtract removed, parent.state_gas_left += child.state_gas_used + child.state_gas_left is sum-conserving and correctly restores the reservoir on revert/halt.

Addresses bullet 3 of #2804.

✅ Checklist

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

  just static

• All: PR title adheres to the repo standard - it will be used as the squash commit message and should start type(scope):.
• All: Considered updating the online docs in the ./docs/ directory.
• All: Set appropriate labels for the changes (only maintainers can apply labels).

[spencer-tb]

Superseded — folded into #2823.