Enforce accepted values for the type attribute of the <exclude-pattern> and <include-pattern> tags

[rodrigoprimo]

Is your feature request related to a problem?

While reviewing #705 (review), I noticed that in the code documentation, PHPCS specifies that there are two possible values for the type attribute of the <exclude-pattern> and <include-pattern> tags that can be used in a ruleset file: absolute and relative.

PHP_CodeSniffer/src/Ruleset.php

Lines 48 to 57 in 9c8f30f

	/**
	* A list of regular expressions used to ignore specific sniffs for files and folders.
	*
	* Is also used to set global exclude patterns.
	* The key is the regular expression and the value is the type
	* of ignore pattern (absolute or relative).
	*
	* @var array<string, array>
	*/
	public $ignorePatterns = [];

PHP_CodeSniffer/src/Ruleset.php

Lines 59 to 68 in 9c8f30f

	/**
	* A list of regular expressions used to include specific sniffs for files and folders.
	*
	* The key is the sniff code and the value is an array with
	* the key being a regular expression and the value is the type
	* of ignore pattern (absolute or relative).
	*
	* @var array<string, array<string, string>>
	*/
	public $includePatterns = [];

But the code does not validate that one of those values is passed and any value is accepted:

PHP_CodeSniffer/src/Ruleset.php

Line 1232 in 9c8f30f

$this->ignorePatterns[$code][(string) $pattern] = (string) $pattern['type'];

PHP_CodeSniffer/src/Ruleset.php

Line 1258 in 9c8f30f

$this->includePatterns[$code][(string) $pattern] = (string) $pattern['type'];

Adding the following to a ruleset.xml file, will add a exclude pattern (called ignore pattern in the code) with the type InvalidValue:

<exclude-pattern type="InvalidValue">./vendor/*</exclude-pattern>

Describe the solution you'd like

PHPCS should validate the values passed to the type attribute and warn users if an invalid value is passed.

Additional context (optional)

• I have read the Contribution Guidelines and this is not a support question.
• I intend to create a pull request to implement this feature.