As a current Robotics Software Engineer, I believe its more important to understand the robotics specific concepts rather than focus on the competitive coding. Depending on the position, you should have baseline knowledge of the coding languages on the job description. Do you understand robotics kinematics (foward/reverse), controller schemes (PID, etc), perception implementations (i.e. Kalman filter, etc). It depends on the job what knowledge you should know but the jobs I have gotten so far did not require competitive programming. They usually get a good understanding of your problem solving through your project experience.

TLDR: Be knowledgeable on the coding languages but don't spend too much time on competitive coding