How to regenerate various sourcegraph.com tokens

This can be regenerated by running:

> openssl rand -hex 16

Note: Existing users will be signed out, but they will be able to sign in again without any issues.

EXECUTOR_FRONTEND_PASSWORD (PRECISE_CODE_INTEL_INTERNAL_PROXY_AUTH_TOKEN)

> openssl rand -base64 128

Needs to be updated in three places:

Follow the instructions for deploying the terraform changes. The dot-com k8s changes are deployed as usual.