A few small changes and feature request

[catap]

Hey,

Thanks for your amazing project. I found shell-xxx quite usefull as well.

So, I'd like to share a few ideas / changes which should improve it usage. Because you have quite complicated strucutre of project and generation, I'd like to summatize everything into one, single, issue. I hope that this is ok.

1. Updated usage of vbox to the last version. Right now some repositories (I've tested shell-netbsd) uses v0.9.4. Was it made for propose or simple forgotten to update?
2. Increase memory usage by vm: GitHub uses different limits for private and public repositories: https://docs.github.com/en/actions/using-github-hosted-runners/about-github-hosted-runners/about-github-hosted-runners and public one has larger limit of CPU and memory. Is it possible to increase default limit to match public settings? I feel that it's good idea, isn't it?
3. It has some issue with high resolution timers, but I have no idea how to speed up in nested virtulization.

Thanks!

[catap]

Regarding (3), it can be, probably, fixed via -rtc clock=vm and -icount qemu options. Or make it worst... Who knows :)

[catap]

And one more feature request: add non-root user to use it by default.

Right now everything runs by root and for software development running tests by root not always good.

Special when you try checks permission of FS :)