fix: Better alignment for Alert icons

[frankieyan]

Short description

This fixes the alignment for icons in the <Alert> component, spotted by @pauloslund over at https://github.com/Doist/todoist-web/pull/8223#pullrequestreview-1706995679

PR Checklist

• [ ] Added tests for bugs / new features
• [ ] Updated docs (storybooks, readme)
• [x] Executed npm run validate and made sure no errors / warnings were shown
• [x] Described changes in CHANGELOG.md
• [x] Bumped version in package.json and package-lock.json (npm --no-git-tag-version version <major|minor|patch>) ref
• [x] Reviewed and approved Chromatic visual regression tests in CI

Versioning

Patch

[frankieyan]

I will take care of this when I'm back after OOO!