test: fix query measurements after 30 days test (#442)

* test: fix query measurements after 30 days test

This test started failing ater 2024-03-10 because
the time at the query was not frozen to a specific
date so it was using the system's actual time and
the measurements were not a part of the last 30 days.

* fix: add comments to clarify test fix

Signed-off-by: joseph-sentry <joseph.sawaya@sentry.io>

utils/tests/unit/test_coverage_measurements.py

@@ -84,7 +84,7 @@ def test_query_monthly_coverage_measurements_after_30_days(self):
         self.add_upload_measurements_records(owner=owner, quantity=3)
         freezer.stop()
 
-        # Now
+        # Uploads within the last 30 days
         freezer = freeze_time("2024-02-10T00:00:00")
         freezer.start()
         self.add_upload_measurements_records(owner=owner, quantity=5)
@@ -94,9 +94,13 @@ def test_query_monthly_coverage_measurements_after_30_days(self):
         assert len(all_measurements) == 8
 
         plan_service = PlanService(current_org=owner)
+        # Now
+        freezer = freeze_time("2024-03-05T00:00:00")
+        freezer.start()
         monthly_measurements = query_monthly_coverage_measurements(
             plan_service=plan_service
         )
+        freezer.stop()
         assert monthly_measurements == 5
 
     def test_query_monthly_coverage_measurements_excluding_uploads_during_trial(self):