Remove `--enable-basic-auth` from the development guide
Remove `--enable-basic-auth` from the development guide

Today, the development guide uses basic auth and causes errors during set up

Basic authentication is deprecated and has been removed in 1.19 and later

Given that we require 1.20, we need to remove this flag in development guide

Reference: https://cloud.google.com/kubernetes-engine/docs/how-to/api-server-authentication

tektoncd/pipeline,tektoncd/pipeline