fix: backport #21673 — prevent HA peer proposals from blocking equivocation in duplicate proposal test

[AztecBot]

Summary

Backport of #21673 to v4-next.

Adds dontStartSequencer: true and skipPushProposedBlocksToArchiver: true to the malicious nodes in the duplicate_proposal_slash e2e test. This prevents HA peer proposals from being added to the archiver, so both malicious nodes build their own blocks instead of one yielding to the other.

Note: v4-next also needed dontStartSequencer: true (from PR #21603) which was already on next when the original PR was merged, so this backport includes both properties.

Conflict Resolution

The cherry-pick conflicted because v4-next lacked the dontStartSequencer: true line added by PR #21603. Resolution was to accept both new properties (dontStartSequencer and skipPushProposedBlocksToArchiver).

Commits

1. Cherry-pick with conflicts (original attempt)
2. Conflict resolution — accept both new properties

Test plan

• duplicate_proposal_slash e2e test should pass with these changes
• No other tests affected (only malicious nodes in this specific test are changed)