Update ocamlformat version
This fixes a problem where the project cannot be solved when with-test is true. It depended on ocamlformat.0.16.0 which in turn depends on ppxlib < 0.22, but this project also depends on ppxlib >= 0.28.0, so no solution was possible.
I came across this problem when trying to solve the project's dependencies with dune package management, which becomes possible after this change.
Can we re-push the commit to re-trigger the CI for this?
I tried but it didn't fix the issue. I don't think it's related to my change.
Indeed, I just opened a PR to fix it: https://github.com/aantron/bisect_ppx/pull/449