feat(ci): set up cirun for gpu tests

[martinkim0]

adds a cirun configuration for GPU tests. given that certain instances may not be available during testing time as well as initialization taking a while, I think it only makes sense to use cirun/aws for multi-gpu tests and keep single-gpu ones on self-hosted.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 88.69%. Comparing base (f53c01a) to head (c85456b).

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2618      +/-   ##
==========================================
- Coverage   89.18%   88.69%   -0.50%     
==========================================
  Files         159      159              
  Lines       13308    13309       +1     
==========================================
- Hits        11869    11804      -65     
- Misses       1439     1505      +66     

see 3 files with indirect coverage changes