Remove `projects` inclusion in `notes_with_associations` to skip some unnecessary queries

`notes_with_associations` are used for `participant` declarations, but `Participable`
only really cares about the target entity project, and not the participants
projects.

`notes_with_associations` are also used in `Commit::has_been_reverted?` which
employs the reference extractor of the commit, so no references to the notes
projects are made there (`Mentionable::all_references` cares only about the
`author` and other `attr_mentionable`). A paralel situation occurs on
`Issue::referenced_merge_requests`.

app/models/commit.rb

@@ -198,7 +198,7 @@ class Commit
   end
 
   def notes_with_associations
-    notes.includes(:author, :project)
+    notes.includes(:author)
   end
 
   def method_missing(m, *args, &block)

app/models/concerns/issuable.rb

@@ -239,7 +239,7 @@ module Issuable
   end
 
   def notes_with_associations
-    notes.includes(:author, :project)
+    notes.includes(:author)
   end
 
   def updated_tasks

app/models/snippet.rb

@@ -102,7 +102,7 @@ class Snippet < ActiveRecord::Base
   end
 
   def notes_with_associations
-    notes.includes(:author, :project)
+    notes.includes(:author)
   end
 
   class << self