CI is slow

[ludfjig]

We should investigate what it takes to speed up CI. I have some suggestions, but I'm sure more can be done. Feel free to add anything I forgot

• Benchmarks on windows runner is very slow compared to linux. We should consider decreasing number of samples needed on windows
• The same wit tests run twice, once for GUEST=c, and once for GUEST=rust, but in this case the tests are identical, so no need to rerun.
• We should be able to trim down some dev-dependencies to improve compile times using cargo features
• Can we cache rust artifacts in github actions cache to improve compile times?

[simongdavies]

One quick win here is there is one windows benchmark that takes a long time , fixing just this will trim minutes off CI:

Benchmarking guest_functions/guest_call_with_large_parameters: Collecting 100 samples in estimated 1193.1 s (100 iterations)