Worker connection failures on startup shouldn't raise errors

[aaronmondal]

At the moment we raise errors when the worker can't find the scheduler:

https://github.com/TraceMachina/nativelink/actions/runs/7558646440/job/20580653217?pr=614#step:9:197

This might lead to issues when running health and readiness checks and readiness checks in K8s. We should find a solution that integrates better with the K8s scheduler.

[MarcusSorealheis]

@aaronmondal does this issue still occur? I don't believe it does.