Functions/StripTags: add support for handling PHP 8.1 first class callables

First class callables are basically syntax sugar for closures.
So:
```php
add_action('my_action', strip_tags(...));
```
... could also be written as:
```php
add_action('my_action', function(...$args) {
    return strip_tags(...$args);
});
```
Example: https://3v4l.org/cra8s#veol

As the code would be flagged when used in a closure, it is my opinion, it should also be flagged when used as a first class callable.

This commit implements this in a WPCS cross-version compatible manner.

Prior to WPCS 3.2.0, first class callables would be send to the `process_no_parameters()` method.
As of WPCS 3.2.0, they will be send to the dedicated `process_first_class_callable()` method. See WordPress/WordPress-Coding-Standards#2544

Author: jrfnl

WordPressVIPMinimum/Sniffs/Functions/StripTagsSniff.php

@@ -74,6 +74,20 @@ public function process_no_parameters( $stackPtr, $group_name, $matched_content
 		$this->add_warning( $stackPtr );
 	}
 
+	/**
+	 * Process the function if it is used as a first class callable.
+	 *
+	 * @param int    $stackPtr        The position of the current token in the stack.
+	 * @param string $group_name      The name of the group which was matched.
+	 * @param string $matched_content The token content (function name) which was matched
+	 *                                in lowercase.
+	 *
+	 * @return void
+	 */
+	public function process_first_class_callable( $stackPtr, $group_name, $matched_content ) {
+		$this->add_warning( $stackPtr );
+	}
+
 	/**
 	 * Add a warning if the function is used at all.
 	 *

WordPressVIPMinimum/Tests/Functions/StripTagsUnitTest.inc

@@ -44,3 +44,5 @@ strip_tags(allowed_tags: $allowed); // Warning. Invalid function call, but that'
 
 \strip_tags(string: $html, allowed_tag: $allowed); // Warning (mind: deliberate typo in param name).
 strip_tags(html: $html); // Warning (mind: deliberately using incorrect param name).
+
+add_action('my_action', strip_tags(...)); // PHP 8.1 first class callable.

WordPressVIPMinimum/Tests/Functions/StripTagsUnitTest.php

@@ -44,6 +44,7 @@ public function getWarningList() {
 			43 => 1,
 			45 => 1,
 			46 => 1,
+			48 => 1,
 		];
 	}
 }