Docs: Add missing documentation for `_WP_Dependency::set_translations()`.

Introduced in [43859].

Props stazdotio.
Fixes #45550.

git-svn-id: https://develop.svn.wordpress.org/trunk@44607 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-includes/class-wp-dependency.php

@@ -112,6 +112,16 @@ class _WP_Dependency {
 		return true;
 	}
 
+	/**
+	 * Sets the translation domain for this dependency.
+	 *
+	 * @since 5.0.0
+	 *
+	 * @param string $domain The translation textdomain.
+	 * @param string $path   Optional. The full file path to the directory containing translation files.
+	 *
+	 * @return bool False if $domain is not a string, true otherwise.
+	 */
 	public function set_translations( $domain, $path = null ) {
 		if ( ! is_string( $domain ) ) {
 			return false;