Allow ignoring/skipping version

[hadogenes]

Create some label in which I could set version which I want to ignore.
e.g. linuxserver/jellyfin has version 2021.12.16 which is bigger than current 10.9.6 and keel want's to upgrade to older version
The linuxserver team doesn't want/can't remove this tag (linuxserver/docker-jellyfin#230)

If there was a label like keel.sh/ignoreVersion: 2021.12.16 that would solve my problem