test failed in CI: test_oximeter_reregistration

[jgallagher]

This test failed on a CI run on #6794:

https://github.com/oxidecomputer/omicron/pull/6794/checks?check_run_id=31733911976

Log showing the specific test failure:

https://buildomat.eng.oxide.computer/wg/0/details/01JAFWKR0V962B2KXK9WB257T0/QuKWDAzMMp3WYt2ahovphvgwOc1gLSM4cCwVzhoqVoR02tm8/01JAFWM1JM94KRNCYGY9J8ZMX7

Excerpt from the log showing the failure:

6316	2024-10-18T13:58:54.822Z	        FAIL [  72.116s] omicron-nexus::test_all integration_tests::oximeter::test_oximeter_reregistration
6317	2024-10-18T13:58:54.822Z	
6318	2024-10-18T13:58:54.822Z	--- STDOUT:              omicron-nexus::test_all integration_tests::oximeter::test_oximeter_reregistration ---
6319	2024-10-18T13:58:54.822Z	
6320	2024-10-18T13:58:54.822Z	running 1 test
6321	2024-10-18T13:58:54.822Z	test integration_tests::oximeter::test_oximeter_reregistration has been running for over 60 seconds
6322	2024-10-18T13:58:54.822Z	test integration_tests::oximeter::test_oximeter_reregistration ... FAILED
6323	2024-10-18T13:58:54.822Z	
6324	2024-10-18T13:58:54.822Z	failures:
6325	2024-10-18T13:58:54.822Z	
6326	2024-10-18T13:58:54.822Z	failures:
6327	2024-10-18T13:58:54.822Z	    integration_tests::oximeter::test_oximeter_reregistration
6328	2024-10-18T13:58:54.822Z	
6329	2024-10-18T13:58:54.822Z	test result: FAILED. 0 passed; 1 failed; 0 ignored; 0 measured; 381 filtered out; finished in 72.07s
6330	2024-10-18T13:58:54.822Z	
6331	2024-10-18T13:58:54.823Z	
6332	2024-10-18T13:58:54.823Z	--- STDERR:              omicron-nexus::test_all integration_tests::oximeter::test_oximeter_reregistration ---
6333	2024-10-18T13:58:54.823Z	log file: /var/tmp/omicron_tmp/test_all-17f1d182e85394d2-test_oximeter_reregistration.151962.0.log
6334	2024-10-18T13:58:54.823Z	note: configured to log to "/var/tmp/omicron_tmp/test_all-17f1d182e85394d2-test_oximeter_reregistration.151962.0.log"
6335	2024-10-18T13:58:54.823Z	DB URL: postgresql://root@[::1]:40485/omicron?sslmode=disable
6336	2024-10-18T13:58:54.823Z	DB address: [::1]:40485
6337	2024-10-18T13:58:54.823Z	log file: /var/tmp/omicron_tmp/test_all-17f1d182e85394d2-test_oximeter_reregistration.151962.2.log
6338	2024-10-18T13:58:54.823Z	note: configured to log to "/var/tmp/omicron_tmp/test_all-17f1d182e85394d2-test_oximeter_reregistration.151962.2.log"
6339	2024-10-18T13:58:54.823Z	log file: /var/tmp/omicron_tmp/test_all-17f1d182e85394d2-test_oximeter_reregistration.151962.3.log
6340	2024-10-18T13:58:54.823Z	note: configured to log to "/var/tmp/omicron_tmp/test_all-17f1d182e85394d2-test_oximeter_reregistration.151962.3.log"
6341	2024-10-18T13:58:54.823Z	thread 'integration_tests::oximeter::test_oximeter_reregistration' panicked at nexus/tests/integration_tests/oximeter.rs:163:14:
6342	2024-10-18T13:58:54.823Z	Failed to retrieve timeseries: TimedOut(60.026376224s)

I strongly suspect this has the same underlying cause as #6895, based on seeing a pruned Oximeter collector in https://buildomat.eng.oxide.computer/wg/0/artefact/01JAFWKR0V962B2KXK9WB257T0/QuKWDAzMMp3WYt2ahovphvgwOc1gLSM4cCwVzhoqVoR02tm8/01JAFWM1JM94KRNCYGY9J8ZMX7/01JAFZZESJF2HPMY867ENBDNQ4/test_all-17f1d182e85394d2-test_oximeter_reregistration.151962.0.log?format=x-bunyan:

2024-10-18T13:57:54.093Z	INFO	test_oximeter_reregistration (oximeter-agent): refreshed list of producers from Nexus
    collector_id = 39e6175b-4df2-4730-b11d-cbc1e60a2e78
    collector_ip = ::1
    file = oximeter/collector/src/agent.rs:809
    n_current_tasks = 1
    n_pruned_tasks = 1