Change acctest GitLab port to 8085
This changes the GitLab instance port from 8080
to 8085
.
The reason for this generally is that 8080
is a very widely used port
and since we map it to localhost may conflict.
More concretely is that the GitLab Configure Team who maintains this
provider also maintains the GitLab Agent for Kubernetes which uses
port 8080
as a default port for the local observability stack and thus
conflicts for me all the time.