MT#57644 puppet/git: allow ssh-rsa pubkey usage

Now that our deployment system is based on Debian/bookworm, but our
gerrit/git server still runs on Debian/bullseye, we run into the OpenSSH
RSA issue (RSA signatures using the SHA-1 hash algorithm got disabled by default), see
https://michael-prokop.at/blog/2023/06/11/what-to-expect-from-debian-bookworm-newinbookworm/
and https://www.jhanley.com/blog/ssh-signature-algorithm-ssh-rsa-error/

We need to enable ssh-rsa usage, otherwise deployment fails with:

| Warning: Permanently added '[gerrit.mgm.sipwise.com]:29418' (ED25519) to the list of known hosts.
| sign_and_send_pubkey: no mutual signature supported
| puppet-r10k@gerrit.mgm.sipwise.com: Permission denied (publickey).
| fatal: Could not read from remote repository.

Change-Id: I5894170dab033d52a2612beea7b6f27ab06cc586

templates/scripts/includes/deployment.sh

@@ -1234,7 +1234,7 @@ puppet_install_from_git() {
   rmdir "${PUPPET_RESCUE_PATH}"
 
   echo "Cloning Puppet git repository from '${PUPPET_GIT_REPO}' to '${PUPPET_LOCAL_GIT}' (branch '${PUPPET_GIT_BRANCH}')"
-  echo 'ssh -i ~/.ssh/id_rsa_r10k -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no $*' > ssh
+  echo 'ssh -i ~/.ssh/id_rsa_r10k -o PubkeyAcceptedKeyTypes=+ssh-rsa -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no $*' > ssh
   chmod +x ssh
   if ! GIT_SSH="${PWD}/ssh" git clone --depth 1 -b "${PUPPET_GIT_BRANCH}" "${PUPPET_GIT_REPO}" "${PUPPET_LOCAL_GIT}" ; then
     die "ERROR: Cannot clone git repository, see the error above, cannot continue!"