Update comments about N + 1 Gitaly calls

To make sure all known issues are linked to the correct epic, I've gone
through the code base, and updated the comments where required.

app/controllers/dashboard/projects_controller.rb

@@ -14,8 +14,7 @@ class Dashboard::ProjectsController < Dashboard::ApplicationController
 
     respond_to do |format|
       format.html do
-        # n+1: https://gitlab.com/gitlab-org/gitlab-ce/issues/37434
-        # Also https://gitlab.com/gitlab-org/gitlab-ce/issues/40260
+        # n+1: https://gitlab.com/gitlab-org/gitlab-ce/issues/40260
         Gitlab::GitalyClient.allow_n_plus_1_calls do
           render
         end

app/controllers/projects/branches_controller.rb

@@ -25,7 +25,7 @@ class Projects::BranchesController < Projects::ApplicationController
         @refs_pipelines = @project.ci_pipelines.latest_successful_for_refs(@branches.map(&:name))
         @merged_branch_names = repository.merged_branch_names(@branches.map(&:name))
 
-        # n+1: https://gitlab.com/gitlab-org/gitaly/issues/992
+        # n+1: https://gitlab.com/gitlab-org/gitlab-ce/issues/48097
         Gitlab::GitalyClient.allow_n_plus_1_calls do
           @max_commits = @branches.reduce(0) do |memo, branch|
             diverging_commit_counts = repository.diverging_commit_counts(branch)

app/controllers/root_controller.rb

@@ -15,7 +15,7 @@ class RootController < Dashboard::ProjectsController
   before_action :redirect_logged_user, if: -> { current_user.present? }
 
   def index
-    # n+1: https://gitlab.com/gitlab-org/gitlab-ce/issues/37434
+    # n+1: https://gitlab.com/gitlab-org/gitlab-ce/issues/40260
     Gitlab::GitalyClient.allow_n_plus_1_calls do
       super
     end

app/models/blob.rb

@@ -110,7 +110,7 @@ class Blob < SimpleDelegator
   end
 
   def load_all_data!
-    # Endpoint needed: gitlab-org/gitaly#756
+    # Endpoint needed: https://gitlab.com/gitlab-org/gitaly/issues/756
     Gitlab::GitalyClient.allow_n_plus_1_calls do
       super(project.repository) if project
     end

app/services/merge_requests/refresh_service.rb

@@ -14,7 +14,9 @@ module MergeRequests
     private
 
     def refresh_merge_requests!
+      # n + 1: https://gitlab.com/gitlab-org/gitlab-ce/issues/60289
       Gitlab::GitalyClient.allow_n_plus_1_calls(&method(:find_new_commits))
+
       # Be sure to close outstanding MRs before reloading them to avoid generating an
       # empty diff during a manual merge
       close_upon_missing_source_branch_ref

lib/banzai/filter/relative_link_filter.rb

@@ -150,7 +150,7 @@ module Banzai
       end
 
       def uri_type(path)
-        # https://gitlab.com/gitlab-org/gitlab-ce/issues/58011
+        # https://gitlab.com/gitlab-org/gitlab-ce/issues/58657
         Gitlab::GitalyClient.allow_n_plus_1_calls do
           @uri_types[path] ||= current_commit.uri_type(path)
         end