fix: deprecate js threepio

[Nolski]

Description

Deprecates Threepio.js as no OpenMined projects are planning on continuing use.

Affected Dependencies

None

Checklist

• [x] I have followed the Contribution Guidelines and Code of Conduct
• [x] I have commented my code following the OpenMined Styleguide
• [x] I have labeled this PR with the relevant Type labels
• [ ] My changes are covered by tests