Disabling some for now since this is based on `Net::LDAP::DN`.

for normalizing and parsing DNs

…to stop copy pasting test cases.

Fix LDAP config key name

See merge request gitlab-org/gitlab-ce!14739

Create idea of read-only database

Closes #37534

See merge request gitlab-org/gitlab-ce!14688

Create merge requests across a fork network

Closes #20097

See merge request gitlab-org/gitlab-ce!14422