[ci] Increase test timeout to work around presumed system contention

[cjllanwarne]

Change Description

Addresses the test failing in https://batch.hail.is/batches/8362516/jobs/172 (test_hail_python_service_backend_gcp_11)

This test appears to be unusually susceptible to cluster contention because (1) it's relatively heavyweight and (2) it has a relatively short custom timeout (all tests have a global 10m timeout, this one overrides it with 4m). In the batch above, I am suspicious that a previous preempted attempt left just enough existing work in place that the retry was just a little too slow to finish.

(It might be nicer to cancel previous attempts' jobs at the start of preemption retries, but that's a much bigger change. Hopefully this will reduce flakiness in the test suite with minimal upfront effort)

Security Assessment

• This change potentially impacts the Hail Batch instance as deployed by Broad Institute in GCP

Impact Rating

• This change has a low security impact

Impact Description

Just a test change to hopefully reduce flakiness

Appsec Review

• Required: The impact has been assessed and approved by appsec