Remove dependencies on Boost.StaticAssert

[Lastique]

Boost.StaticAssert has been merged into Boost.Config, so remove the dependency.

[pdimov]

I'm going to merge this, because without it, we get error like

error: Unable to find file or target named
error:     '/boost/static_assert//boost_static_assert'
error: referred to from project at
error:     '/home/runner/work/boost_install/boost-root/libs/wave/build'
error: could not resolve project reference '/boost/static_assert'

now.

[jefftrull]

Yikes thanks

[pdimov]

This also needs to go to master, but since you have other pending changes on develop, I can't merge it, so I'll leave that to you.