Migrate gating tests from STI to FMF

What were you trying to do that didn't work?

We are unable to run gating tests in CentOS Stream merge requests due to a bug in Testing Farm. The bug (RHEL) was not resolved because STI (Standard Test Interface) for gating tests which we use is deprecated. As a result of that, we decided to migrate the gating tests to the supported FMF (Flexible Metadata Format).

Please provide the package NVR for which bug is seen:

N/A, this is a build issue

How reproducible:

Create a MR in CentOS Stream distgit, wait for Zuul CI to finish, rpm-sti-test will end with FAILURE due to missing source files.

Expected results

Gating tests are run in the CentOS Stream MR.

Actual results

Gating tests fail in the CentOS Stream MR due to a bug.