Create a reusable-ubuntu-ci yaml file to be used in all the branches (such as master and 4.0.x-devel) with all the steps and a ubuntu-ci yaml file passing the specific parameters. Already introduced here.
Remove the filter on the branches of the pull-request trigger, in this way the job will run on all the PRs (not only the ones open on master)
Add a step to determine Fast DDS branch to be used. It checks if there is a branch passed as input, otherwise it checks if there is a branch of FastDDS with the same name of FastDDS-Gen branch and if it doesn't use the default branch.
@Mergifyio backport 2.5.x, 2.1.x