Handle when user is nil for PAT notification

Add a nil check for current_user
while determining if a banner is required
to be shown for PAT expiration.

ee/app/helpers/ee/user_callouts_helper.rb

@@ -89,6 +89,8 @@ module EE
     end
 
     def show_token_expiry_notification?
+      return false unless current_user
+
       !token_expiration_enforced? &&
         current_user.active? &&
         !user_dismissed?(PERSONAL_ACCESS_TOKEN_EXPIRY, 1.week.ago)

ee/spec/helpers/ee/user_callouts_helper_spec.rb

@@ -371,6 +371,17 @@ RSpec.describe EE::UserCalloutsHelper do
       it do
         expect(subject).to be result
       end
+
+      context 'when user is nil' do
+        before do
+          allow(helper).to receive(:current_user).and_return(nil)
+          allow(helper).to receive(:token_expiration_enforced?).and_return(false)
+        end
+
+        it do
+          expect(subject).to be false
+        end
+      end
     end
   end