Add Windows and macOS CI tests and only run coverage on Ubuntu with latest Julia version

[efaulhaber]

This produces the following runs:

1. Ubuntu latest, Julia latest. This is our "main run" and it's running unit tests with coverage and uploading to Codecov.
2. Ubuntu latest, Julia 1.9.
3. Windows latest, Julia latest.
4. macOS-ARM, Julia latest.

Closes #435.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 70.84%. Comparing base (3189426) to head (7616c74).

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #444   +/-   ##
=======================================
  Coverage   70.84%   70.84%           
=======================================
  Files          66       66           
  Lines        3807     3807           
=======================================
  Hits         2697     2697           
  Misses       1110     1110           

Flag	Coverage Δ
unit	70.84% <ø> (ø)

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[sloede]

FWIW, I'd additionally run

• macOS (x64), Julia latest
• Ubuntu latest, Julia v1.8

though with a reduced test set. If you are only able to run the full testset, then it's probably too much though

[efaulhaber]

We don't have a reduced test set (yet).

[svchb]

1.8 doesn't really work since there is this timestepping bug in OrdinaryDiffEq.jl that was fixed in a version, which has julia compat 1.9.

[efaulhaber]

1.8 doesn't really work since there is this timestepping bug in OrdinaryDiffEq.jl that was fixed in a version, which has julia compat 1.9.

You're right. It doesn't make sense to support Julia 1.8. This bug made a lot of simulations abort with "instability detected" when using saving and postprocess callback.
IIRC, this was SciML/OrdinaryDiffEq.jl#1616, fixed by SciML/OrdinaryDiffEq.jl#2098.