Docs: Correct the variable name passed to the determine_locale filter.

Follow-up to [43776], [44134].

Props truptikanzariya.
Fixes #60167.

git-svn-id: https://develop.svn.wordpress.org/trunk@57233 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-includes/l10n.php

@@ -161,7 +161,7 @@ function determine_locale() {
 	 *
 	 * @since 5.0.0
 	 *
-	 * @param string $locale The locale.
+	 * @param string $determined_locale The locale.
 	 */
 	return apply_filters( 'determine_locale', $determined_locale );
 }