Figure out the infrastructure for long running tests

[alxiord]

Some, if not all, crates will require long running tests for more relevant performance measurements, as well as stability and more. This might resolve into dedicated Buildkite pipelines for each crate and may not be centralized in rust-vmm-ci, but until that's ironed out, we'll be tracking the matter in one issue. We can follow up with per-crate issues if it resolves to that.