split macos tests in 2

[Dr-Irv]

follow up to #43468 to also split MacOS tests in half to speed up CI tests per comment from @jreback #43468 (comment)

[mzeitlin11]

On a run like https://dev.azure.com/pandas-dev/pandas/_build/results?buildId=66005&view=results, the test distribution looks like windows1: gw0 [104233] / gw1 [104233], windows2: gw0 [26865] / gw1 [26865] and windows1 seems to take generally longer (and saw a timeout yesterday, can't remember which pr). Maybe we can add a few more letters to the second job to even out?

[jbrockmendel]

Looking at the Windows timeouts, the last lines before the timeout nearly all look like they are making HTTP requests, e.g.

....ss......ss......ss.x.x.xxss......ss......ss......ss................127.0.0.1 - - [10/Sep/2021 21:05:19] "GET / HTTP/1.1" 200 - 

I could totally imagine something in the network stack blocking and not having a timeout set.

[Dr-Irv]

On a run like https://dev.azure.com/pandas-dev/pandas/_build/results?buildId=66005&view=results, the test distribution looks like windows1: gw0 [104233] / gw1 [104233], windows2: gw0 [26865] / gw1 [26865] and windows1 seems to take generally longer (and saw a timeout yesterday, can't remember which pr). Maybe we can add a few more letters to the second job to even out?

Good observation. I moved it by one letter. There are a lot of tests in the "i" category, so let's see how this change helps.

[Dr-Irv]

Split now gw0 [74211] / gw1 [74211] on Windows1 and gw0 [56887] / gw1 [56887] on Windows2

[jreback]

thanks @Dr-Irv

[jreback]

@meeseeksdev backport 1.3.x