Update test to new behavior

If the dates have not changed, the date picker is not reinitialized and
its dates are not set again. So switching "Working-days only" checkbox
no longer shows the current date again and it's not needed for the test
to wait for the current date to be displayed and switch back to the
correct date.

spec/features/work_packages/datepicker/datepicker_follows_relation_spec.rb

@@ -69,13 +69,7 @@
 
       datepicker.toggle_working_days_only
       datepicker.expect_working_days_only false
-      # Toggling non-working days reinitializes the displayed flatpickr, which
-      # shows the current date again. We need to wait for it to be reinitialized
-      # before showing another date. Ideally the flatpickr should not be
-      # reinitialized if it does not need to (dates not changed for instance).
-      datepicker.expect_visible_day Date.current
 
-      datepicker.show_date "2024-02-05"
       datepicker.expect_disabled Date.parse("2024-02-05")
       datepicker.expect_disabled Date.parse("2024-02-04")
       datepicker.expect_disabled Date.parse("2024-02-03")