DEV: Return only valid repos

This will stop non-upgradeable plugins from showing up on the list. This mainly means core plugins like `poll` or `chat`

app/controllers/docker_manager/admin_controller.rb

@@ -21,7 +21,6 @@ module DockerManager
         result[:fork] = true if result[:official] &&
           !r.url.starts_with?("https://github.com/discourse/")
 
-        if r.valid?
         result[:id] = r
           .name
           .downcase
@@ -35,7 +34,6 @@ module DockerManager
           result[:upgrading] = true
           result[:version] = r.upgrade_version
         end
-        end
 
         result
       end

lib/docker_manager/git_repo.rb

@@ -84,7 +84,8 @@ class DockerManager::GitRepo
 
     Discourse.visible_plugins.each do |p|
       next if p.name == "docker_manager"
-      repos << DockerManager::GitRepo.new(File.dirname(p.path), p.name)
+      repo = DockerManager::GitRepo.new(File.dirname(p.path), p.name)
+      repos << repo if repo.valid?
     end
 
     repos