Gitlab versions in conflict in Ubuntu after manual dpkg install

Hi all. I upgraded 10.6 to 10.8 by way of downloading the deb package and doing a manual sudo dpkg -i file.deb and now dpkg reports conflicts between 10.6 and 10.8:

ic  gitlab-ce                             10.6.4-ce.0                         amd64        GitLab Community Edition (including NGINX, Postgres, Redis)
ii  gitlab-ee                             10.8.6-ee.0                         amd64        GitLab Enterprise Edition (including NGINX, Postgres, Redis)

I would like to remove 10.6.4 but I really really don’t want to destroy the gitlab install.

10.6.4 was installed by having in my /etc/apt/sources.list.d directory.

Any tips? Thank you.