perf(db): drop redundant db-side migrations version sorting

[joshtrichards]

• Resolves: #

Summary

Since we sort in PHP in the way we want to, the db-side sorting is just extra CPU burn.

Notes:

• The only real change here is line 179
  • Related historical context: fix(migration): Correctly sort migrations by version number #47515
• The other changes are just some tech debt/cleanup:
  • the addition of runtime typing (that was partially missing throughout the class).
  • updating of the comments for createMigrationTable() since it has some serious side effects worth knowing about.

Checklist

• Code is properly formatted
• Sign-off message is added to all commits
• Tests (unit, integration, api and/or acceptance) are included
• Screenshots before/after for front-end changes
• Documentation (manuals or wiki) has been updated or is not required
• Backports requested where applicable (ex: critical bugfixes)
• Labels added where applicable (ex: bug/enhancement, 3. to review, feature component)
• Milestone added for target branch/version (ex: 32.x for stable32)

AI (if applicable)

• The content of this PR was partly or fully generated using AI