Summary
The current standalone WT CI setup does not include testing on ARM64.

Motivation
The MongoDB server runs on ARM, and tests WT directly. But there may be parts of WT that are not current exercised by the server regression testing, and it would be better to catch any ARM specific issues in WT itself before finding them via indirect testing with the MongoDB server.

Is this issue urgent?
Somewhat urgent, as ARM64 is increasingly important in the clould.

Acceptance Criteria (Definition of Done)
This ticket can be considered done when there are ARM64 build variants on the various WiredTiger evergreen waterfalls that are peers with the other architectures in terms of the scope of testing.

Testing
No specific testing, as the request is simply for more testing.

Documentation update
No.