d/rules: switch to --gem-install layout
Update d/rules so dh_ruby installs the gem when building the package.
FTR it is being used in Ubuntu, as of https://launchpad.net/ubuntu/+source/ruby-childprocess/4.1.0-2ubuntu1
Update d/rules so dh_ruby installs the gem when building the package.
FTR it is being used in Ubuntu, as of https://launchpad.net/ubuntu/+source/ruby-childprocess/4.1.0-2ubuntu1