Docs: Fix parameter rendering for Abilities API functions

[Adi-ty]

This PR fixes rendering issues in the "Parameters" section for wp_register_ability() and wp_register_ability_category() on the Developer Hub. The issue is caused by a collision between modern PHP generic syntax (array<string, mixed>) and the legacy "hash notation" parser used by the DevHub theme. When these are combined, the parser fails to correctly identify the variable name, leading to malformed text being displayed on the site.

Trac ticket: https://core.trac.wordpress.org/ticket/65074

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[github-actions]

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