package/containerd: security bump to version 1.6.12
CVE-2022-23471: https://github.com/advisories/GHSA-2qjp-425j-52j9
and other bugfixes, see:
https://github.com/containerd/containerd/releases/tag/v1.6.12
Signed-off-by: Christian Stewart <christian@paral.in>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>