Minor Issues Identified in `runner` at `validator/client/runner.go`

[yhassanzadeh13]

💎 Issue

Background

I noticed a few minor issues with runner at validator/client/runner.go:

1. slotCtx is not cancelled upon return, which may cause a context leakage.
2. span is not closed on all execution paths, e.g., here.
3. It seems that slotCtx can be better scoped, e.g., in this invocation, slotCtx seems a more appropriate option than the general ctx due to its scope.

I can proceed with a PR if we have a shared agreement on the enhancements related to these minor issues.

Description