use Vec::with_capacity avoid realloc

[nkysggsy]

[Link to related issue(s) here, if any]

[Short description of the changes.]
use Vec::with_capacity avoid realloc

Checklist

• Breaking changes are clearly marked as such in the PR description and changelog
• New behavior is reflected in tests
• If performance characteristic of an instruction change, update gas costs as well or make a follow-up PR for that
• The specification matches the implemented behavior (link update PR if changes are needed)

Before requesting review

• I have reviewed the code myself
• I have created follow-up issues caused by this PR and linked them here

After merging, notify other teams

[Add or remove entries as needed]

• Rust SDK
• Sway compiler
• Platform documentation (for out-of-organization contributors, the person merging the PR will do this)
• Someone else?

[fuel-cla-bot]

Thanks for the contribution! Before we can merge this, we need @nkysggsy to sign the Fuel Labs Contributor License Agreement.