Disable CLA Bot

[npatki]

Problem Description

When external users submit PRs, there is currently a CLA assistant bot that auto-responds asking them to sign an agreement. This CLA bot is out-of-date, as we have a more robust agreement available to e-sign upon request.

Expected behavior

Disable the CLA bot. For external PRs, a member of the SDV team will manually respond with instructions for the e-sign agreement.