* Switch compiler builds and tests to GitHub actions
* Expose ${cc} in ocamltest
* Allow lib-bigarray-2/bigarrfml.ml to run on 32-bit
* Simplify environment variables passed to scripts
* Reduce matrix to 3 builds
* Move minimum build into Jenkins other-configs
As discussed among the core OCaml developers.
This commit adds a Github action that "pings" issues that have been inactive for one year and schedules them for closing 30 days later if no action has been taken.