Fix broken dora4 spec

By default dora4 metrics controller returns data for last 3 months

We use 2021-01-01 as fixture date in specs.

So controllers stoped returning this data on 2021-04-02

Also, max range was calculated as 91 days, while it's actually
possible to have 92 days in 3 months.
I caught this trying to fix the issue

ee/app/services/dora/aggregate_metrics_service.rb

@@ -2,7 +2,7 @@
 
 module Dora
   class AggregateMetricsService < ::BaseContainerService
-    MAX_RANGE = 3.months / 1.day
+    MAX_RANGE = 92 # the maximum number of days in 3 months
     DEFAULT_ENVIRONMENT_TIER = 'production'
     DEFAULT_INTERVAL = Dora::DailyMetrics::INTERVAL_DAILY
 

ee/spec/requests/api/dora/metrics_spec.rb

@@ -15,7 +15,7 @@ RSpec.describe API::Dora::Metrics do
     let(:user) { maintainer }
 
     around do |example|
-      freeze_time do
+      travel_to '2021-01-03'.to_time do
         example.run
       end
     end