Some npm packages strictly require a specific npm version because npm
don't handle some version requirements the same way in 1.0 and 2.0.
However, Nix don't use npm for dependency resolution (this is always
achieved with npm 1.0 criteria by npm2nix), so these requirements turns
out to be pointless and just crashes some package installations.
This patch removes npm requirements so the packages can still be built.
This solves #5787.
25ce27b45e