[CI] arm-unittest-matrix runs without timeouts

[atoulme]

Component(s)

No response

Describe the issue you're reporting

The build for ARM should have a timeout of 30 minutes globally.

[crobert-1]

Out of ignorance, why would the timeout be 30 minutes for the entire run, instead of a specific step or part of the run?

[asreehari-splunk]

I believe it was mostly related to the cost associated with the github action runners. CNCF asked to put a limit on it

[crobert-1]

Is this limit the running time of tests, or run count? (Or both?)