Test_CLI_Experiment_AssignmentContextInTelemetry has flaky cleanup in CI

[ellismg]

Seen this a few times over the past week. I don't think this is the same as previous telemetry related issue's we've seen in CI where azd was running in a folder and holding a lock on it via the CWD.

=== FAIL: cli/azd/test/functional Test_CLI_Experiment_AssignmentContextInTelemetry (0.18s)
    experiment_test.go:28: DIR: /tmp/Test_CLI_Experiment_AssignmentContextInTelemetry3693077042/001
    testing.go:1225: TempDir RemoveAll cleanup: unlinkat /tmp/Test_CLI_Experiment_AssignmentContextInTelemetry3693077042/002/telemetry: directory not empty

Possible that there was a race where a sub-process of azd (maybe the uploader?) is writing stuff to this directory as it's trying to get cleaned up?