Allow disabling retries

**What would you like to be added**:

Allow disabling request retries.

**Why is this needed**:

When using `--request-timeout`, the timeout applies to each individual request and not the command as a whole. If a context is unreachable, commands like `kubectl exec` (which don't retry) time out after `--request-timeout`. However, commands like `kubectl get` it will retry the command so it times out much later since it has to timeout multiple times before the command finishes.