metis 4.0.3

Add version 4.0.3 to metis package. Attempted to implement reasonable
versions of all variants declared for metis@5.1.0; some of these do
not have analogues in metis@4.0.3, and errors are raised accordingly.

Also updated dependencies of packages with depends_on('metis') to
depends_on('metis@5:') to ensure that these packages still build.