test failed in CI: test_delete_volume_region_snapshot_replacement_step

[karencfv]

This test failed on a CI run on #8904:

https://github.com/oxidecomputer/omicron/pull/8904/checks?check_run_id=48931785958

Log showing the specific test failure:

https://buildomat.eng.oxide.computer/wg/0/details/01K3J19M1RS3J07KWF9AQFYZ0N/v3OqcPjAjqspzvvGiT6y1aBO3eAk8ozSXjI0SxqXotuQ7Ikz/01K3KMMZ8V4GYZJ43VH6SWVCCZ#S7436

Excerpt from the log showing the failure:

stderr ───
  log file: /var/tmp/omicron_tmp/test_all-916b4bf438c2e923-test_delete_volume_region_snapshot_replacement_step.22873.0.log
  note: configured to log to "/var/tmp/omicron_tmp/test_all-916b4bf438c2e923-test_delete_volume_region_snapshot_replacement_step.22873.0.log"
  DB URL: postgresql://root@[::1]:35361/omicron?sslmode=disable
  DB address: [::1]:35361
  log file: /var/tmp/omicron_tmp/test_all-916b4bf438c2e923-test_delete_volume_region_snapshot_replacement_step.22873.2.log
  note: configured to log to "/var/tmp/omicron_tmp/test_all-916b4bf438c2e923-test_delete_volume_region_snapshot_replacement_step.22873.2.log"
  log file: /var/tmp/omicron_tmp/test_all-916b4bf438c2e923-test_delete_volume_region_snapshot_replacement_step.22873.3.log
  note: configured to log to "/var/tmp/omicron_tmp/test_all-916b4bf438c2e923-test_delete_volume_region_snapshot_replacement_step.22873.3.log"
  
  thread 'integration_tests::crucible_replacements::test_delete_volume_region_snapshot_replacement_step' panicked at nexus/tests/integration_tests/crucible_replacements.rs:1653:21:
  bad result from create_region_snapshot_replacement_step
...