triggerable step with docker latent worker

Python version: 3.10.4
Buildbot version: 3.5.0
Twisted version: 22.4.0

In my buildbot setup I have added Docker Latent worker with custom docker image.

```
worker.DockerLatentWorker('fw-build-docker-sign', '',
docker_host='tcp://fw-build-d2:2375',
image='buildbot-worker/sign',
volumes=['/home/build/.azure:/home/build/.azure',
'/home/build/packages:/home/build/packages',
'/mnt/artifacts:/mnt/artifacts'],
hostconfig={'network_mode': 'host'},
followStartupLogs=True,
max_builds=1,
hostname='signing_docker_worker'),

```

All is working as expected except for the triggerable step which is in use to call the builder on this worker, sometimes the step returns success without actually running the triggered build. The main build is waiting for some time (20-40 seconds) to get the worker available and sometimes returns success without invoking the build.

```
f.addStep(steps.Trigger(name="Signing %s packages" % t1,
schedulerNames=['signing_docker_scheduler'],
waitForFinish=True,
sourceStamps=[{'revision': Property('sdk'), 'codebase': ''}],
set_properties={'factory': util.Property('%sfactorypackage' % t1),
'field': util.Property('%sfieldpackage' % t1),
'target': Property('target'),
'TYPE': t1,
'dst_folder': Property('nbf'),
'action': azure_sign_action,
},
haltOnFailure=True))
```

When there are more than one request for the build, sometimes the build does not run and it returns success and no build URL in the buildbot webUI shows up.

I have been using steps.Trigger for a while and have not seen any issues with not docker based workers.

Might it be a buildbot issue ?

Start with the DockerLatentWorker configuration and the steps.Trigger usage shown in the report. Reproduce the behavior with multiple queued requests while checking whether the latent worker becomes available and whether the triggered build is created. Done means identifying why Trigger can report success without a build URL and adding coverage for the failure case.

Written by the indexing model from the issue text.