[DRE-maint] Bug#1063478: gem2deb rails assets smoke test should handle links or skip the test during build

[Pirate Praveen]

Package: gem2deb
Version: 2.2.1
Sevrity: important

For majority of packages that wraps javascript assets, the actual assets 
are shipped in a libjs-* package and ruby-* package only include a 
symbolic link.

At present, this means, the test will always fail in such cases since 
dh_link step is not yet run when this test is run.

Details here https://lists.debian.org/debian-ruby/2024/02/msg00006.html

So I think we have a few options,

1. Run this only as an autopkgtest (like how it is currently done) which 
will have the links
2. Run this tests after dh_link is done
3. Manually run dh_link before this test

To reproduce this bug, you can build this branch 
https://salsa.debian.org/ruby-team/ruby-jquery-rails/-/tree/debian-tests-assets?ref_type=heads