Eclipse ESCET builds fail: Failed to add the RSA host key for IP address '141.94.179.217' to the list of known hosts (/home/jenkins/.ssh/known_hosts).

The Eclipse ESCET builds fail due to the following error:

 > git fetch --no-tags --force --progress -- git@gitlab.eclipse.org:eclipse/escet/escet.git +refs/heads/develop:refs/remotes/origin/develop # timeout=10
ERROR: Error cloning remote repo 'origin'
hudson.plugins.git.GitException: Command "git fetch --no-tags --force --progress -- git@gitlab.eclipse.org:eclipse/escet/escet.git +refs/heads/develop:refs/remotes/origin/develop" returned status code 128:
stdout: 
stderr: Failed to add the RSA host key for IP address '141.94.179.217' to the list of known hosts (/home/jenkins/.ssh/known_hosts).
Permission denied (publickey,gssapi-keyex,gssapi-with-mic).
fatal: Could not read from remote repository.

Please make sure you have the correct access rights
and the repository exists.

See e.g. https://ci.eclipse.org/escet/job/ESCET%20build/job/develop/41/console

Here is the full log, for archival purposes: escet-develop-41.txt

We use the centos-7 pod.

It seems something in the pod template got changed or so, removing write access to /home/jenkins/.ssh/known_hosts?