devel/R-cran-gert: update to 2.1.0
Add LICENSE_FILE.
Add "compiles" option to uses-cran so don't need STRIP_CMD and
NO_ARCH_IGNORE.
Changelog: https://cloud.r-project.org/web/packages/gert/NEWS
PR: 280802
Approved by: Jean-Paul Beconne <jpbeconne@free.fr> (maintainer)