Remove CoreManager `SERVER_AUTH_TYPE` and `SERVER_AUTH_TOKEN` configs

[dplewis]

New Feature / Enhancement Checklist

• I am not disclosing a vulnerability.
• I am not just asking a question.
• I have searched through existing issues.

Current Limitation

These are no longer needed as CoreManager REQUEST_HEADERS has been added to handle global headers. This is a breaking change

[parse-github-assistant]

🚀 Thanks for opening this issue! We are excited about your ideas for improvement!

[parseplatformorg]

🎉 This change has been released in version 7.0.0-alpha.1

[parseplatformorg]

🎉 This change has been released in version 7.0.0