feat: Build with node 18

[rapotl]

Summary of changes 🔍

Now that we got off the node-sass and that will free us up to get to node 18 which is currently in LTS. Dart-sass exposes the same JS API so it's a drop-in replacement.

Testing 🧪

• I ran the build locally and in the pipelines to make sure those worked.
• I ran storybook and it looks like all the styling stuff is still looking good.

Checklist ✔️

• [x] Linked associated issue (if present)
• [x] Added relevant labels
• [x] Requested developer reviews
• [x] Request UI review from design / PM
• [ ] Verify all code checks are passing