onekey: disable NKRO and mousekeys by default

[fauxpark]

Description

⚠ handwired/onekey/bluepill_f103c6: Feature mousekey is specified in both info.json and rules.mk, the rules.mk value wins.
⚠ handwired/onekey/bluepill_f103c6: Feature nkro is specified in both info.json and rules.mk, the rules.mk value wins.

These features are hard to properly test with only a single key, and with CI in place checking that it at least compiles is already done.

Types of Changes

• Core
• Bugfix
• New feature
• Enhancement/optimization
• Keyboard (addition or update)
• Keymap/layout/userspace (addition or update)
• Documentation

Issues Fixed or Closed by This PR

Checklist

• My code follows the code style of this project: C, Python
• I have read the PR Checklist document and have made the appropriate changes.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• I have tested the changes and verified that they work and don't break anything (as well as I can manage).