chore: Migrate custom-404-static.test.js to node:test

[ktym4a]

Changes

• Part of ☂️ Move Astro tests to node:test  #9873
• Migrates packages/astro/test/custom-404-static.test.js

Testing

All tests pass.

Docs

Test-only changes.

[changeset-bot]

⚠️ No Changeset found

Latest commit: 2df2e50

Merging this PR will not cause a version bump for any packages. If these changes should not result in a new version, you're good to go. If these changes should result in a version bump, you need to add a changeset.

Click here to learn what changesets are, and how to add one.

Click here if you're a maintainer who wants to add a changeset to this PR