* index/li/libblas/libblas-external.toml: uncomment the msys2 origin
and make it to lapack. The reason is that we require libblas.dll,
and this isn't provided by openblas (lapack provides both).
Also, add an empty origin for macos.
* index/li/liblapack/liblapack-external.toml: uncomment the msys2
origin.
Also, add an empty origin for macos.
These only support linux; not needed on macOS, and the msys2 libraries can't
be installed because of key signing errors.
* index/li/libblas/libblas-external.toml
* index/li/liblapack/liblapack-external.toml