is_dashboard_ready error causes wait_ready to crash

[ChristianZaccaria]

Describe the Bug

Based on this Slack thread by @Maxusmusti

The is_dashboard_ready check errors out when the cluster/appwrapper is still in a pending state, causing wait_ready to crash.

Steps to Reproduce the Bug

1. Run cluster.up() and cluster.wait_ready() together.
2. See the error.

Potential solution

Checking if the dashboard is ready AFTER the cluster is ready, instead of both at every timestep from the start.