- 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
* r-igraph: find old packages in the archive
Fixes#6104.
* r-irlba: find old packages in the archive
Fixes#6101.
* r-lazyeval: find old packages in the archive
Fixes#6102.
* packages: set list_url for all packages hosted on CRAN
* packages: consistently use the CRAN archive URLs
* Add several new R packages
* Add a few more R packages
* Update more versions
* Convert Package to RPackage
* Add a few more packages
* Add missing dependencies
