Upgrade vite, vitest (#588)

- https://github.com/microbit-foundation/python-editor-v3/security/dependabot/65
- https://github.com/microbit-foundation/python-editor-v3/security/dependabot/63

Dev tooling issue only.
Audit issues remain re node-fetch via tensorflow and d3 color, neither of which
are a practical concern.

Author: microbit-matt-hillsdon