[CI]: Split build-test job into three stages

## Proposed Stages

### Stage 1

Low cost GitHub instance that checks linter / clippy.

### Stage 2

Large GCE instance that cross-compiles test artifacts for the next stage.

### Stage 3

Low cost GCE instance that runs pre-compiled tests. Tests are not parallel and it would be cost prohibitive to run all of them on the largest instance.
