Remove redundancy with examples tested in CI, optimize

[austinabell]

As asked by #694 (comment), there is some redundancy on what is tested in the CI. Currently, the buildkite machine builds and tests all examples and the CI tests most examples with linux and mac machines.

If we want everything to be tested on both archs, we should remove the testing step in buildkite and update the CI to test all examples (and possibly optimize so it isn't just split in half without creating a new job for each specifically).

Low priority currently as this isn't a bottleneck, but could still save dev time