Remove outdated versions

Remove outdated GitLab version references.

doc/administration/packages/container_registry.md

@@ -6,10 +6,6 @@ info: To determine the technical writer assigned to the Stage/Group associated w
 
 # GitLab Container Registry administration **(FREE SELF)**
 
-> - [Introduced](https://gitlab.com/gitlab-org/gitlab-foss/-/merge_requests/4040) in GitLab 8.8.
-> - Container Registry manifest `v1` support was added in GitLab 8.9 to support
->   Docker versions earlier than 1.10.
-
 With the GitLab Container Registry, every project can have its
 own space to store Docker images.
 
@@ -832,8 +828,6 @@ no longer directly accessible via the `:latest` tag.
 
 ### Recycling unused tags
 
-> [Introduced](https://gitlab.com/gitlab-org/omnibus-gitlab/-/merge_requests/987) in Omnibus GitLab 8.12.
-
 Before you run the built-in command, note the following:
 
 - The built-in command stops the registry before it starts the garbage collection.
@@ -910,8 +904,6 @@ When the command is used without the `-m` flag, the Container Registry only remo
 
 ### Performing garbage collection without downtime
 
-> [Introduced](https://gitlab.com/gitlab-org/omnibus-gitlab/-/merge_requests/764) in GitLab 8.8.
-
 You can perform garbage collection without stopping the Container Registry by putting
 it in read-only mode and by not using the built-in command. On large instances
 this could require Container Registry to be in read-only mode for a while.