fix: Fix phpdoc typing for IL10N::l $data parameter

The implementation supports passing null and our code is using that,
 reflect it in the public API.

Signed-off-by: Côme Chilliet <come.chilliet@nextcloud.com>

lib/private/L10N/L10N.php

@@ -117,7 +117,7 @@ class L10N implements IL10N {
 	/**
 	 * Localization
 	 * @param string $type Type of localization
-	 * @param \DateTime|int|string $data parameters for this localization
+	 * @param \DateTime|int|string|null $data parameters for this localization
 	 * @param array $options
 	 * @return string|int|false
 	 *

lib/public/IL10N.php

@@ -50,7 +50,7 @@ interface IL10N {
 	/**
 	 * Localization
 	 * @param string $type Type of localization
-	 * @param \DateTime|int|string $data parameters for this localization
+	 * @param \DateTime|int|string|null $data parameters for this localization
 	 * @param array $options currently supports following options:
 	 *                       - 'width': handed into \Punic\Calendar::formatDate as second parameter
 	 * @return string|int|false