Fix YARN test

[kevin-bates]

Looks like the YARN tests are timing out because the Application ID is not getting conveyed. Since this is a mocked environment, something has probably side-affected things and it should be relatively straightforward to locate the issue.

Here's a build failure log: https://github.com/jupyter-server/gateway_provisioners/actions/runs/6187008029/job/16795884972

followed by some relevant text:

------------------------------ Captured log call -------------------------------
INFO     traitlets:yarn.py:293 YarnProvisioner: kernel launched. YARN RM: my-yarn-cluster.acme.com:7777, pid: 42, Kernel ID: 64bea58e-8b2d-4bd7-a916-17d52f02a35f, cmd: '['--public-key:MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQCu87zbdvcyLCV7Ownj5nMbwDYpIZtxOoYONKIO7A3ulZosjRmRqzDPUivKBnK7fp5DKOEpBZlnyxc89Xglg/Zbneu4QY8AQ5oZntFTegUFbF1zk/KzQUSDFRHiPqxKs1C7WlJU4wOSbnpvZOmUuOXJZKULsFGrzLgXMH09RNS+3QIDAQAB', '--response-address:10.213.5.248:8880', '--port-range:0..0', '--kernel-id:64bea58e-8b2d-4bd7-a916-17d52f02a35f']'
ERROR    traitlets:remote_provisioner.py:339 KernelID: '64bea58e-8b2d-4bd7-a916-17d52f02a35f' launch timeout due to: Application ID is None. Failed to submit a new application to YARN within 30 seconds.  Check server log for more information.