Fix migration in migrate_epic_notes_mentions_to_db_spec.rb

The spec for the migration assumed that the primary ID for notes started
at 1, but if another migration ran before it that would change the
sequence. We can fix this by hard-coding the IDs in the spec to start at
1.

Closes https://gitlab.com/gitlab-org/gitlab/issues/199297

ee/spec/migrations/migrate_epic_notes_mentions_to_db_spec.rb

@@ -16,9 +16,9 @@ describe MigrateEpicNotesMentionsToDb, :migration, :sidekiq do
     namespaces.create!(id: 1, name: 'group1', path: 'group1', owner_id: 1)
     epics.create!(id: 1, iid: 1, title: "title", title_html: 'title', description: 'epic description', group_id: 1, author_id: 1)
 
-    notes.create!(note: 'note1 for @root to check', noteable_id: 1, noteable_type: 'Epic')
-    notes.create!(note: 'note2 for @root to check', noteable_id: 1, noteable_type: 'Epic', system: true)
-    notes.create!(note: 'note3 for @root to check', noteable_id: 1, noteable_type: 'Epic')
+    notes.create!(note: 'note1 for @root to check', id: 1, noteable_id: 1, noteable_type: 'Epic')
+    notes.create!(note: 'note2 for @root to check', id: 2, noteable_id: 1, noteable_type: 'Epic', system: true)
+    notes.create!(note: 'note3 for @root to check', id: 3, noteable_id: 1, noteable_type: 'Epic')
   end
 
   it 'schedules epic mentions migrations' do