We should remove these tools from the requirements:

• fprime-fpl-convert-xml==1.0.3
• fprime-fpl-extract-xml==1.0.3
• fprime-fpp-to-xml==3.0.0a16

When I tried this, the build worked, but the visualizer complained as follows:

[WARNING] Could not find fprime-fpp-to-xml in requirements file
Built target refresh_cache
[ERROR] Context must be a Path

Needed to complete nasa/fpp#732.