Tests: Use correct comparison in `do_enclose()` tests.

As per the PHP manual:
> If the `component` parameter is omitted, an associative array is returned.
> If the `component` parameter is specified, `parse_url()` returns a string (or an int, in the case of `PHP_URL_PORT`) instead of an array. If the requested component doesn't exist within the given URL, `null` will be returned.

Reference: [https://www.php.net/manual/en/function.parse-url.php#refsect1-function.parse-url-returnvalues PHP Manual: parse_url(): Return Values]

In this case, `parse_url()` is called with the `PHP_URL_PATH` as `$component`, but the returned value is subsequently checked against `false`.

In other words, this condition would previously always result in `true` and would lead to `null` potentially being passed to the PHP native `pathinfo()` function which expects a string.

On PHP 8.1, this would result in a test failure with a `pathinfo(): Passing null to parameter #1 ($path) of type string is deprecated` error.

Reference: [https://www.php.net/manual/en/function.pathinfo.php PHP Manual: pathinfo()]

Follow-up to [46175].

Props jrf.
See #53635.
Built from https://develop.svn.wordpress.org/trunk@51606


git-svn-id: http://core.svn.wordpress.org/trunk@51217 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/version.php

@@ -13,7 +13,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '5.9-alpha-51605';
+$wp_version = '5.9-alpha-51606';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.