Pyyaml is available as a Debian package (python3-yaml),
for the sake of simplicity or reproducibility it may be preferable to install that package instead of running pip when preparing the Docker image
https://github.com/iNavFlight/inav/blob/1fa4ac29e6b1f2f518c61dc3053005b280579c4b/Dockerfile#L11C17-L11C23

Please ping me if there is something else you need packaged in Debian.