Ensure Omnibus Docker image has exiftool deps
Ensure Omnibus Docker image has exiftool deps

- Install the MRO perl library required by exiftool since version 11.86
  since it seems it is not present by default on Ubuntu 20

Related https://gitlab.com/gitlab-org/omnibus-gitlab/-/issues/4288

Closes https://gitlab.com/gitlab-org/omnibus-gitlab/-/issues/6951

Changelog: fixed
Signed-off-by: Robert Marshall <0465b3b4f3ae0103ad50d09ff86a3523700a2979@gitlab.com>

gitlabhq/omnibus-gitlab,gitlabhq/omnibus-gitlab,gitlabhq/omnibus-gitlab,gitlabhq/omnibus-gitlab