FIX: Do not raise if post no longer exists (#12428)

app/jobs/regular/export_user_archive.rb

@@ -304,7 +304,7 @@ module Jobs
         .where(user_id: @current_user.id)
         .where(post_action_type_id: PostActionType.types[:like])
         .each do |pa|
-        post = Post.with_deleted.find(pa.post_id)
+        post = Post.with_deleted.find_by(id: pa.post_id)
         yield [
           pa.id,
           pa.post_id,

spec/jobs/export_user_archive_spec.rb

@@ -396,6 +396,7 @@ describe Jobs::ExportUserArchive do
       PostActionCreator.like(user, post3)
       PostActionCreator.like(admin, post3)
       PostActionDestroyer.destroy(user, post3, :like)
+      post3.destroy!
 
       data, csv_out = make_component_csv
       expect(data.length).to eq(2)