Bug: Validation: Placeholder replacement not working for complex validation rules

[element-code]

When using the following Syntax for the rules, Validation::fillPlaceholders() cant find the rules and fails to replace any placeholders

$rules = [
	'email' => [
		'rules' => ['required', 'trim', 'valid_email', 'max_length[191]', 'is_unique[users.email, id, {id}]'],
	]
]

Validation::run() handles this for the validation itself:

CodeIgniter4/system/Validation/Validation.php

Lines 172 to 173 in b8ad778

	// Blast $rSetup apart, unless it's already an array.
	$rules = $rSetup['rules'] ?? $rSetup;

PR Incomming

[kenjis]

It seems the way to set rules with array is not documented.
Am I overlooked it?