test failed in CI: `app::background::tasks::populate_switch_ports::tests::test_switch1_comes_up_late`

This test failed on a CI run on #10534:

https://github.com/oxidecomputer/omicron/pull/10534/checks?check_run_id=79570615602

Log showing the specific test failure:

https://buildomat.eng.oxide.computer/wg/0/details/01KT7G8DCZ660QZZ4JWBYT8F5M/vKy6chpHoq098zym3392IT9aQ8BAK409vTvnqGsFV29od6cB/01KT9RZQ0RY5NGSMDTHB5156BH#S9793

Excerpt from the log showing the failure:

2026-06-04T17:31:41.225Z	  stdout ───
2026-06-04T17:31:41.225Z	
2026-06-04T17:31:41.225Z	    running 1 test
2026-06-04T17:31:41.225Z	    test app::background::tasks::populate_switch_ports::tests::test_switch1_comes_up_late has been running for over 60 seconds
2026-06-04T17:31:41.225Z	  stderr ───
2026-06-04T17:31:41.225Z	    log file: /var/tmp/omicron_tmp/omicron_nexus-841e1fd6fbb51d9c-test_switch1_comes_up_late.16170.0.log
2026-06-04T17:31:41.225Z	    note: configured to log to "/var/tmp/omicron_tmp/omicron_nexus-841e1fd6fbb51d9c-test_switch1_comes_up_late.16170.0.log"
2026-06-04T17:31:41.226Z	    DB URL: postgresql://root@[::1]:62611/omicron?sslmode=disable
2026-06-04T17:31:41.226Z	    DB address: [::1]:62611
2026-06-04T17:31:41.226Z	    log file: /var/tmp/omicron_tmp/omicron_nexus-841e1fd6fbb51d9c-test_switch1_comes_up_late.16170.2.log
2026-06-04T17:31:41.226Z	    note: configured to log to "/var/tmp/omicron_tmp/omicron_nexus-841e1fd6fbb51d9c-test_switch1_comes_up_late.16170.2.log"
2026-06-04T17:31:41.226Z	    log file: /var/tmp/omicron_tmp/omicron_nexus-841e1fd6fbb51d9c-test_switch1_comes_up_late.16170.3.log
2026-06-04T17:31:41.226Z	    note: configured to log to "/var/tmp/omicron_tmp/omicron_nexus-841e1fd6fbb51d9c-test_switch1_comes_up_late.16170.3.log"
2026-06-04T17:31:41.226Z	
2026-06-04T17:31:41.226Z	    (test timed out)

Looks like cargo-nextest timed this out after 900s, and then the next run passed right away, after just 6.2s