chore(tests): use logMaxFileCount instead of a environment variable in tests MONGOSH-2009

[gagik]

Previously we relied on MONGOSH_TEST_ONLY_MAX_LOG_FILE_COUNT for setting max log files. Now we can do so by defining a global config for tests.

[gagik]

Not sure if this is the best way to go about it (also will see how CI reacts...; seems good so far)

[alenakhineika]

Maybe we can create a file during testing, write to it, and then delete it as a test suit cleanup. Similarly how we do here: https://github.com/mongodb-js/mongosh/blob/main/packages/e2e-tests/test/e2e.spec.ts#L1463-L1467

[addaleax]

Yeah, or you could just do config.set(...) in one shell and then start another one, we also do that in a couple of places (has the advantage of not requiring any explicit disk I/O)

[gagik]

my thinking was to make it consistent with everything that would otherwise be using the environment variable so at least in both cli-repl and e2e-tests which is why I thought to keep the actual settings being set in setup-env.sh instead of some package's test setup code.

Isn't it better to have this global file instead of the alternatives? It seems less restricted to any given package and avoids more computation of building a file or spawning shells for every test.