Exclude increment/decrement Sniff that conflicts with our standard

[jaymcp]

Description

The Universal.Operators.DisallowStandalonePostIncrementDecrement Sniff from WPCS conflicts with the SlevomatCodingStandard.Operators.DisallowIncrementAndDecrementOperators Sniff that adheres to our coding standard of preference for +=/-= over ++/--.

Types of changes (if applicable):

• Bug fix (non-breaking change which fixes an issue).
• New feature (non-breaking change which adds functionality).
• Breaking change (fix or feature that would cause existing functionality to not work as expected).

Checklist (if applicable):

• All checks pass when running `composer run all-checks.