Add `cargo semver-checks` to CI

[szokeasaurusrex]

Cargo semver-checks identifies breaking changes to the public API. We should add this to our CI process so we get notified when a PR introduces a breaking change. By default, the check should fail CI if a breaking change is detected, but of course, we sometimes need to make breaking changes, so we can suppress the failure by adding a "breaking change" label to the PR or by indicating the breakage in the PR title

Related to #1164

[linear-code]

RUST-239