flake: `TestGetUserStatusCounts`

[ethanndickson]

Looks like this test has broken with the US moving to daylight savings, it only runs with postgres and it's failed on all postgres-using CI jobs.
https://github.com/coder/coder/actions/runs/13752449408
https://github.com/coder/coder/actions/runs/13756567387

e.g.

=== FAIL: coderd/database TestGetUserStatusCounts/America/New_York/User_deleted_during_query_range (0.53s)
    t.go:106: 2025-03-09 21:04:28.690 [debu]  pubsub: pubsub dialing postgres  network=tcp  address=127.0.0.1:5432  timeout_ms=0
    t.go:106: 2025-03-09 21:04:28.690 [debu]  pubsub: pubsub postgres TCP connection established  network=tcp  address=127.0.0.1:5432  timeout_ms=0  elapsed_ms=0
    t.go:106: 2025-03-09 21:04:28.716 [debu]  pubsub: pubsub connected to postgres
    t.go:106: 2025-03-09 21:04:28.716 [debu]  pubsub: pubsub has started
    querier_test.go:3334: 
        	Error Trace:	/home/runner/work/coder/coder/coderd/database/querier_test.go:3334
        	Error:      	Not equal: 
        	            	expected: 0
        	            	actual  : 1
        	Test:       	TestGetUserStatusCounts/America/New_York/User_deleted_during_query_range
    t.go:106: 2025-03-09 21:04:29.077 [info]  pubsub: pubsub is closing
    t.go:106: 2025-03-09 21:04:29.077 [info]  pubsub: pubsub listen stopped receiving notify
    t.go:106: 2025-03-09 21:04:29.077 [debu]  pubsub: pubsub closed

[johnstcn]

This part of GetUserStatusCounts looks sus:

WITH
	-- dates_of_interest defines all points in time that are relevant to the query.
	-- It includes the start_time, all status changes, all deletions, and the end_time.
dates_of_interest AS (
	SELECT date FROM generate_series(
		@start_time::timestamptz,
		@end_time::timestamptz,
		(CASE WHEN @interval::int <= 0 THEN 3600 * 24 ELSE @interval::int END || ' seconds')::interval
	) AS date
),