CI: Speed up ci build that keeps timing out

[jarrodmillman]

Reference issue

What does this implement/fix?

Additional information

[tylerjereddy]

We still have pretty solid Python 3.8 coverage in CI, so I don't mind putting it in to see if it helps.

That said, skimming through the recent timing reports for this job, it seems to fluctuate between 40-something minutes and > 1 hour timeouts, and we've already seen pretty wide fluctuations in Azure job runtimes that may be related to what hardware gets assigned on the backend, which I think is a partial motivation for migration to GHA per gh-15814.

For example, this PR (#16108) from you yesterday has the original CI config passing the job 1 minute faster than with your adjustment here, so I do have at least a healthy dose of skepticism that this stuff is entirely in our hands as far as the Azure service is concerned.

[tylerjereddy]

thx