Update EOS Image and versionlock to 5.3.9
Summary
The versionlock change only affects the clients we run in CI (i.e. in the cta-client-0 pod and the ones needed for taped.
Additional Required Actions
- Requires manual tests in pre-production: NO
- Requires a documentation update: NO
References
Closes #1126 (closed)
Edited by Niels Alexander Buegel