Improve local backend detection

[zc-devs]

Automatically detect Local backend only if Agent is NOT running in container.
Closes #3996.

[qwerty287]

This actually makes it impossible to use the local backend in containers. Maybe the better solution is to just drop the auto-detect option and set docker as default value?

[zc-devs]

Maybe the better solution is to just drop the auto-detect option and set docker as default value?

What's about entirely dropping default and auto-detect option?

[qwerty287]

I'd still set a default as I think most users use the docker backend. If docker is not available it will fail anyways.

[6543]

This actually makes it impossible to use the local backend in containers. Maybe the better solution is to just drop the auto-detect option and set docker as default value?

oh right ... let me fix it

[zc-devs]

backend == "local" || !inContainer

That is exactly what I've just wanted to write! :)

[qwerty287]

This breaks it if you use command line args instead of env vars. Please change this to use the CLI context (similar to docker)