- 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
* Release 2.0 of the ECP Proxy Apps suite
* update laghos version
* make install dir structure consistent across all ecp-proxy-apps
* minor
* update macsio version