- remove the old LGPL license headers from all files in Spack
- add SPDX headers to all files
- core and most packages are (Apache-2.0 OR MIT)
- a very small number of remaining packages are LGPL-2.1-only
The edit phase of cbench was used to set environment variables. Though
this works, the variables set this way are not dumped to build.env.
This commit fixes the issue by setting those variables in the
`setup_environment` function.
