Revert "support/testing: generate runtime test jobs with runner tags"

The CI minute cost estimate is wrong for two reasons:
  1) Job duration was in minutes instead of seconds
  2) The cost factor is really 0,5 [1] instead of
     based on runner type * 0,5.

Due to this two mistake, the real CI minute cost is 7982.1 [2] instead
of 350.

Since we want to backport this patch, having a correct CI minute cost
estimate in the commit log would be better. Lets revert last changes
about runner tag and try again.

[1] https://docs.gitlab.com/ci/pipelines/compute_minutes/#cost-factors-of-hosted-runners-for-gitlabcom
[2] https://gitlab.com/buildroot.org/buildroot/-/pipelines/2562421098

This reverts commit 38039415f8.
This reverts commit 825abb2682

Signed-off-by: Romain Naour <romain.naour@smile.fr>
Signed-off-by: Arnout Vandecappelle <arnout@rnout.be>

support/testing/tests/package/test_mender.py

@@ -57,7 +57,6 @@ class TestMenderRO(TestMenderInfra):
         self.run_mender_test()
 
 
-# gitlab-runner: large
 class TestMenderSystemd(TestMenderInfra):
     config = \
         """