Remove 2> /dev/null in Terraform kubectl wait

[NimJay]

Background

• We added 2> /dev/null to the end of the kubectl wait command in our Terraform in when we added DeployStack support.
• Purpose of 2> /dev/null: it silences standard errors logged by kubectl wait.
• I think we only did this to make the DeployStack output cleaner.
• But we should avoid silencing errors in general.

Change Summary

• Unsilence kubectl wait errors.

Testing Procedure

• No testing necessary as this is a trivial change.

Additional info

• This is the first step to investigating terraform apply errs on kubectl wait #1813 — an error with the kubectl wait command.