Errors after setting `enableAnonymousUsers: false`

New Issue Checklist

• I am not disclosing a vulnerability.
• I am not just asking a question.
• I have searched through existing issues.
• I can reproduce the issue with the latest version of Parse Server.

Issue Description

I had anonymous users enabled in my server, but after changing enableAnonymousUsers: true to false I get a lot of errors when querying the _User class/list in the Parse dashboard and from Cloud code.

TypeError: Cannot read properties of undefined (reading 'afterFind')
  at /home/parse/node_modules/parse-server/lib/Adapters/Auth/index.js:204:11
  at Array.map (<anonymous>)
  at Object.runAfterFind (/home/parse/node_modules/parse-server/lib/Adapters/Auth/index.js:197:32)
  at /home/parse/node_modules/parse-server/lib/RestQuery.js:698:85
  at Array.map (<anonymous>)
  at RestQuery.handleAuthAdapters (/home/parse/node_modules/parse-server/lib/RestQuery.js:698:43)
  at /home/parse/node_modules/parse-server/lib/RestQuery.js:201:17
  at process.processTicksAndRejections (node:internal/process/task_queues:95:5)

All anonymous users have been deleted from the database but that did not solve the problem.
All other classes load fine but not the _User class.

Steps to reproduce

Add anonymous users when enableAnonymousUsers: true and convert some of them into real users (with an email).
Set enableAnonymousUsers: false and query the _User class.

Actual Outcome

Server error, no results are returned.

Expected Outcome

The query to work.

Environment

Server

• Parse Server version: 6.2.1
• Operating system: Ubuntu server 20.04
• Local or remote host (AWS, Azure, Google Cloud, Heroku, Digital Ocean, etc): remote VPS

Database

• System (MongoDB or Postgres): MongoDB
• Database version: 4.4.22
• Local or remote host (MongoDB Atlas, mLab, AWS, Azure, Google Cloud, etc): remote VPS

Client

• SDK (iOS, Android, JavaScript, PHP, Unity, etc): Parse dashboard / Cloud code
• SDK version: 5.1.0 / 6.2.1

Logs

Crashes at line 235 since adapter is null.
https://github.com/parse-community/parse-server/blob/a742656a90a3db73b5d2087c4643a144637ae6bb/src/Adapters/Auth/index.js#L213-L235

Fixed by

I replaced enableAnonymousUsers: false with

auth: {
    anonymous: {
      enabled: false
    }
  }

and it no longer crashes.

Start in src/Adapters/Auth/index.js around lines 213-235, then reproduce the issue by creating anonymous users, disabling enableAnonymousUsers, and querying the _User class. Compare the failing configuration with the working auth.anonymous.enabled setting; done means _User queries from the dashboard and Cloud Code return results without a server error.