ptl-tool: log the ceph-ci push (and the equivalent git command)

ptl-tool: log the ceph-ci push (and the equivalent git command)

Previously, a real (non-dry-run) push of the integration branch/tag to
ceph-ci was silent -- only the "[DRY RUN] Would push ..." path logged
anything. Add matching log.info() calls on the real-push path, and
include the literal `git push <remote> <ref>` invocation in the message
so it can be copy-pasted and re-run manually if needed (e.g. after a
network blip, or to re-push without re-running the whole merge).

Signed-off-by: Yuri Weinstein <yweinste@redhat.com>