Upcoming/proposed changes to the automatic tests (CI) on GitHub

[Matthias Koeppe]

Posting per Travis's suggestion in https://github.com/sagemath/sage/pull/36938#issuecomment-1870827695 to ask for feedback on these changes. 

Any constructive feedback from the "developer experience" side of things is welcome -- here or on the PRs! It is not necessary to be familiar with the internals of the implementation of the CI. 

CI Build & Test: Show doctest failures, warnings as annotations in the 'Files changed' tab (https://github.com/sagemath/sage/pull/36938)

- Status quo: One has to open the log, searching for "Failed example" and then looking up the source code by line numbers

- Improvement: The doctest failures are annotated right next to the doctest in the "Changed files" tab (see https://github.com/sagemath/sage/pull/36558/files for an illustration)

- Possible downside: Cluttering of the diff view in the PR when there are many annotations for failed doctests

Other changes to the CI:

Separate jobs for pyright, build, modularized tests, long tests (https://github.com/sagemath/sage/pull/36498)

- Status quo: "Build & Test" runs for 2.5 hours, then reports green checkmark in the PR box

- Improvement: "Build" (including test of modified files) runs for 20 minutes, then reports green checkmark; full test runs separately (< 2.5 hours), then reports green checkmark; the technical steps "get_ci_fixes" are removed from the PR box

CI conda: On pull_request, only run 1 macOS job and 1 Linux job (https://github.com/sagemath/sage/pull/36694)

- Status quo: PR box shows 3 CI conda jobs for Linux and 3 CI conda jobs for macOS

- Improvement: PR box only shows 2 jobs; and the macOS jobs no longer queue up 

[Matthias Koeppe]

All of these are still waiting for review