DEV: Clean up state to prevent flaky tests (#27397)

When adding custom translations for tests using `I18n.backend.store_translations`,
we need to remove the custom translations at the end of each test to
prevent the custom translations from leaking to other tests.

plugins/automation/spec/serializers/automation_serializer_spec.rb

@@ -41,6 +41,7 @@ describe DiscourseAutomation::AutomationSerializer do
       DiscourseAutomation::Scriptable.add("foo") do
         field :bar, component: :text, triggerable: DiscourseAutomation::Triggers::TOPIC
       end
+
       I18n.backend.store_translations(
         :en,
         {
@@ -56,6 +57,8 @@ describe DiscourseAutomation::AutomationSerializer do
       )
     end
 
+    after { I18n.backend.reload! }
+
     context "when automation is not using the specific trigger" do
       fab!(:automation) do
         Fabricate(
@@ -72,6 +75,7 @@ describe DiscourseAutomation::AutomationSerializer do
             scope: Guardian.new(user),
             root: false,
           )
+
         expect(serializer.script[:templates]).to eq([])
       end
     end