adopt Depot action runner

[turadg]

What is the Problem Being Solved?

Some of jobs are very slow. Issues with measurements,

• parallel execution of a3p-integration tests #11000

Description of the Design

We can do certain optimizations but an easy global one is to adopt Depot's Action Runners.

Security Considerations

Building off GitHub. Negligible because we already build the SDK image using Depot's remote Docker builder.

Scaling Considerations

n/a

Test Plan

TBD

Upgrade Considerations

n/a

[mhofman]

@usmanmani1122 this is probably gonna become really needed once we add the follower to a3p-integration. The performance of github runners is abysmal and I believe if we want to share the a3p build for the matrixed tests, we do need the caching abilities of depot for that.