Refs #27666 - Clean up sass-rails pinning

This is semantically the same, but makes it a bit easier on the
packaging side where we have a script that converts it into the RPM
spec. Previously it generated:

Requires: %{?scl_prefix_ror}rubygem(sass-rails) >= 5.0
    Requires: %{?scl_prefix_ror}rubygem(sass-rails) < 6.0
    Requires: %{?scl_prefix_ror}rubygem(sass-rails) < 6

After it generates:

Requires: %{?scl_prefix_ror}rubygem(sass-rails) >= 5.0
    Requires: %{?scl_prefix_ror}rubygem(sass-rails) < 6.0