Build system was changed to use a Makefile. Therefore older versions
(which don't support this) are removed. The new build system also
supports testing by default.
- 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
* Fixed a few small bugs in the 'git-lfs' install script.
* Fixed a bug in the '(go|go-bootstrap)@1.4.2+test' install scripts.
* Fixing a minor style issue in the 'git-lfs' install script.
