Changes

OBS: cleanup: new script

Add a script for cleaning old sources uploaded to OBS. This was needed
as we were running out of space on the OBS server, due to source
tarballs being generated in nightly jobs (e.g. Osmocom_OBS_nightly and
never getting deleted). This script is now running automatically every
day.

The script does the following:
* Iterate over all OBS projects and packages inside the projects.
* Delete all source files matching *.dsc, *.tar.xz in old revisions from
  disk, which are not in the most recent revision anymore.
* Create an empty file instead (as otherwise OBS becomes unstable)
* Write a marker file with the revisions already iterated through (per
  project+package) and skip those on the next run.

Related: SYS#7407
Change-Id: I4649dedf0bb52f0bbdc7577ac0bc9e93cb3be192

jobs/ttcn3-testsuites-testenv: Add ttcn3-pcap-client-test-io_uring

Since osmo-pcap.git Change-Id I72e8a6ceb4fb1eb70372e13bb139ead0e2bc0860,
osmo-pcap-client uses osmo_stream which in turn uses osmo_io (which can
u io_uring backend).
Hence, add io-uring backend to the test matrix for this project.

Change-Id: I817b4d27cd2e8faabf2ebb5ad28f025535571282