perf(relayer): optimize timeout processing with drain and Vec

[songgaoye]

Closes: #XXX

Description

The optimization provides 40-44% performance improvement across all batch sizes by:

• Replacing HashMap with Vec for sequential index access

• Eliminating cloning by using drain() instead of iter() + clone()

• Pre-allocating vector capacity

Batch Size	Legacy (clone)	Optimized (drain)	Improvement
32	286 µs	171 µs	40%
64	548 µs	321 µs	41%
128	1,115 µs	640 µs	43%

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PR author checklist:

• Added changelog entry, using unclog.
• Added tests: integration (for Hermes) or unit/mock tests (for modules).
• Linked to GitHub issue.
• Updated code comments and documentation (e.g., docs/).
  • If guide has been updated, tag GitHub user mircea-c
• Tagged one reviewer who will be the one responsible for shepherding this PR.

Reviewer checklist:

• Reviewed Files changed in the GitHub PR explorer.
• Manually tested (in case integration/unit/mock tests are absent).

[socket-security]

Review the following changes in direct dependencies. Learn more about Socket for GitHub.

Diff	Package	Supply Chain Security	Vulnerability	Quality	Maintenance	License
	cargo/​clap@​4.5.54
	cargo/​criterion@​0.5.1

View full report

[randy-cro]

Looks fine to me but probably wanna take into account some of the refactoring upstream PR/changes provided by the reviewer? Also could we somehow test this on devnet (can use the attestation-layer one actually since there are ibc events every x blocks) to see if there are any bugs or is there significant improvement

[songgaoye]

updated