Eliminate N+1 queries referencing issues

To load issue 1, we see that in #38033 that about 835 ms of the
SQL queries were due to loading ProjectFeature. We should be
able to cut this down by eagerly loading this information.

Closes #38033

changelogs/unreleased/sh-project-feature-eager-load.yml

@@ -0,0 +1,5 @@
+---
+title: Eliminate N+1 queries referencing issues
+merge_request:
+author:
+type: fixed

lib/banzai/reference_parser/issue_parser.rb

@@ -34,7 +34,8 @@ module Banzai
                 { namespace: :owner },
                 { group: [:owners, :group_members] },
                 :invited_groups,
-                :project_members
+                :project_members,
+                :project_feature
               ]
             }
           ),