Clean up build dependencies

[tjni]

I think these two dependencies do not need to be specified in pyproject.toml:

1. setuptools_scm_git_archive does not seem to be needed unless a .git_archival.txt file exists
2. wheel does not need to be specified: setuptools defines a get_requires_for_build_wheel function in its build backend that does this automatically

[ssbarnea]

Add a git archival file, would help people wanting to install from git archive.