Remove `Parse.Query.withCount` method

[mtrezza]

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

Support for `` requires a type ambiguity in the Parse.Query.findAll signature. Since moving to TypeScript, type ambiguities are apparent and should be removed. See #2621 (comment).

[parse-github-assistant]

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