Install docker-buildx for Ubuntu

Since docker 23, the legacy builder is deprecated. It is needed
to install the package "docker-buildx".

Output example:
root@u22ovn:/tmp# docker build -t frr frr_docket
DEPRECATED: The legacy builder is deprecated and will be removed in a
            future release. Install the buildx component to build
            images with BuildKit:
            https://docs.docker.com/go/buildx/

This package is not present in CentOS nor Fedora.

Related-Bug: #2088166
Change-Id: I8024fc8c0b73c52044826c9850d20ecc6fbb2fb6
1 file changed