Fix test flakiness by forcing work packages order

`WorkPackage.all` could return the work packages in any order, which can
occasionnally make the test fail as it expects the results in a certain
order.

spec/models/journable/with_historic_attributes_spec.rb

@@ -149,7 +149,7 @@
     end
 
     context "with active record relation of work packages" do
-      let(:work_packages) { WorkPackage.all }
+      let(:work_packages) { WorkPackage.order(subject: :asc).all }
 
       it "provides access to the work-package attributes" do
         expect(subject.map(&:subject)).to eq ["The current work package 1", "The current work package 2"]
@@ -246,7 +246,7 @@
     end
 
     context "with active record relation of work packages" do
-      let(:work_packages) { WorkPackage.all }
+      let(:work_packages) { WorkPackage.order(subject: :asc).all }
 
       it "provides access to the work-package attributes at timestamps" do
         expect(subject.first.attributes_by_timestamp["2022-01-01T00:00:00Z"].subject).to eq "The original work package 1"