Use Depot hosted runners instead of GHA hosted runners.

[benjyw]

Depot have reached out about this, so I want to see how easy it is.

[benjyw]

Nice! The Depot Linux x86 shards seem to be quite a bit faster than on GHA hardware. But I need to do a fully uncached build on both to verify apples-to-apples.

[cburroughs]

👀 oh cool, is that a REAPI offering too? https://depot.dev/products/cache

[sureshjoshi]

Oh damn, Depot coming in hot... A Pants client used them, and they were wayyy faster

[benjyw]

We now have access to their macos runners, so this should all pass. Once this is in I will look at switching to them for Linux ARM as well, and to trying out their REAPI offering.

[sureshjoshi]

Is there a rough estimate on how much faster these are? The CI is tricky, since it sporadically uses cache.

Also, for running CI in forks, this would/should fail out of the box right? This is my ignorance related to how Depot was setup on the backend (e.g. is it whitelisted? Would this apply to scie-pants too?)

[benjyw]

Is there a rough estimate on how much faster these are? The CI is tricky, since it sporadically uses cache.

Also, for running CI in forks, this would/should fail out of the box right? This is my ignorance related to how Depot was setup on the backend (e.g. is it whitelisted? Would this apply to scie-pants too?)

This PR was on a fork and it worked...

[sureshjoshi]

Is there a rough estimate on how much faster these are? The CI is tricky, since it sporadically uses cache.
Also, for running CI in forks, this would/should fail out of the box right? This is my ignorance related to how Depot was setup on the backend (e.g. is it whitelisted? Would this apply to scie-pants too?)

This PR was on a fork and it worked...

It was a PR from your fork to pantsbuild/pants right?

I'm referring to running CI in the fork itself.

[benjyw]

Ah, that would require a separate depot account for that fork I think.

So perhaps this should be switchable?

[sureshjoshi]

Ah, that would require a separate depot account for that fork I think.

So perhaps this should be switchable?

Nahhh, no part of the Pants offering or documentation is making GHA in other forks work out of the box. It doesn't today anyways. I was just checking, as I have a patch that I can apply (or we can make the generate script handle this).

Not important as part of this PR.

[cburroughs]

🚀 ! Excited to see these in action.