Fix ci_deleted_objects#pick_up_at

Ref: #463245

What does this MR do and why?

This MR fixes a bug where pick_up_at attributes was inheriting from ci_job_artifacts#expire_at attributes and it was set far away in the future.

We are now defaulting to a much lower value so the artifacts will get purged instead of staying around forever.

Example of invalid records

gitlabhq_dblab=# select pick_up_at from ci_deleted_objects where project_id is null order by pick_up_at desc limit 30;
 3357-11-12 18:16:55.948546+00
 3357-11-12 18:16:55.883574+00
 3357-11-12 18:15:24.405893+00
 3357-11-12 18:15:24.365412+00
 3357-11-12 18:13:26.599447+00
 3357-11-12 18:13:26.297623+00
 3357-11-12 18:12:52.241059+00
 3357-11-12 18:12:52.169821+00
 3024-06-05 14:40:53.589939+00
 3024-06-05 14:40:53.589939+00
 3024-06-05 14:40:28.874439+00
 3024-06-05 14:40:28.874439+00
 3024-06-05 14:28:20.742851+00
 3024-06-05 14:28:20.742851+00
 3024-06-05 14:11:59.991901+00
 3024-06-05 14:11:59.991901+00
 3024-05-29 09:18:18.686627+00
 3024-05-29 09:18:18.686627+00
 3024-05-15 15:37:43.547515+00
 3024-05-15 15:37:43.547515+00
 3024-05-15 15:29:15.35861+00
 3024-05-15 15:29:15.35861+00
 3024-02-22 09:58:07.819327+00
 3024-02-22 09:58:07.819327+00
 3024-01-23 00:07:03.4891+00
 3024-01-23 00:07:03.4891+00
 3024-01-23 00:06:08.684529+00
 3024-01-23 00:06:08.684529+00
 3024-01-23 00:04:24.338185+00
 3024-01-23 00:04:24.338185+00
 3023-12-05 04:30:32.361139+00
 3023-12-05 04:30:32.361139+00
 3023-09-07 14:57:38.860684+00
 3023-09-07 14:57:38.860684+00
 3023-09-07 14:54:26.9994+00
 3023-09-07 14:54:26.9994+00
 3023-08-16 19:31:53.471082+00
 3023-08-16 19:31:53.471082+00
 3023-08-01 08:09:21.9718+00
 3023-08-01 08:09:21.9718+00
 3023-08-01 08:06:49.201734+00
 3023-08-01 08:06:49.201734+00
 3023-07-20 14:30:00.835269+00
 3023-07-20 14:30:00.835269+00
 3023-07-20 14:24:56.496691+00
 3023-07-20 14:24:56.496691+00
 3023-07-20 14:12:08.683728+00
 3023-07-20 14:12:08.683728+00
 3023-07-20 14:04:41.640952+00
 3023-07-20 14:04:41.640952+00
 3023-07-20 12:17:22.671222+00
 3023-07-20 12:17:22.671222+00
 3023-07-20 12:16:45.208268+00
 3023-07-20 12:16:45.208268+00
 3023-06-27 05:17:15.517611+00
 3023-06-27 05:17:15.517611+00
 3022-12-09 16:23:10.032655+00
 3022-12-09 16:23:09.98492+00
 3022-12-09 16:23:01.066555+00
 3022-12-09 16:23:01.032919+00
 3022-09-16 14:15:06.061087+00
 3022-09-16 14:15:06.045186+00
 3022-09-09 09:39:55.685078+00
 3022-09-09 09:39:55.658363+00
 3022-09-09 09:39:38.419342+00
 3022-09-09 09:39:38.399638+00
 3022-07-28 19:58:00.673143+00
 3022-07-28 19:58:00.635531+00
 3022-07-28 19:57:20.025844+00
 3022-07-28 19:57:20.011264+00
 3022-07-28 19:54:44.085847+00
 3022-07-28 19:54:44.03628+00
 3021-06-17 13:45:21.145681+00
 3021-06-17 13:45:21.140956+00
 3020-12-10 17:49:26.05258+00
 3020-12-10 17:49:26.04959+00
 3020-12-10 17:48:36.14073+00
 3020-12-10 17:48:36.137642+00
 3018-09-30 20:42:13.539862+00
 3018-09-30 20:42:13.510583+00
 3018-09-30 20:41:54.971207+00
 3018-09-30 20:41:54.94379+00
 3018-09-30 20:17:09.564742+00
 3018-09-30 20:17:09.54478+00
 3018-09-30 20:14:35.942966+00
 3018-09-30 20:14:35.915004+00
 2224-03-17 04:33:36.21341+00
 2224-03-17 04:33:36.21341+00
 2224-03-17 04:07:20.775722+00
 2224-03-17 04:07:20.775722+00
 2124-02-14 14:15:28.111788+00
 2124-02-14 14:15:28.111788+00
 2124-02-14 07:45:49.092131+00
 2124-02-14 07:45:49.092131+00
 2124-02-13 17:04:34.396371+00
 2124-02-13 17:04:34.396371+00
 2124-02-13 12:38:09.102667+00
 2124-02-13 12:38:09.102667+00
 2124-02-13 09:49:00.591961+00
 2124-02-13 09:49:00.591961+00
(100 rows)