Makefile: update buildx to v0.9.0
release notes: https://github.com/docker/buildx/releases/tag/v0.9.0
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
(cherry picked from commit f27b74f0f7dd41f09f806a08f6855259c19e965b)
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>