Script Loader: Correct the number of arguments passed to WP_Styles::get_etag().

This fixes an issue with the usage of the new `$wp_styles->get_etag()` method in `wp-admin/load-styles.php`, where `$wp_version` is passed as the first argument instead of `$load` being used as the ''only'' argument.

Follow-up to [58935].

Props justlevine, mukesh27, swissspidy.
See #52217, #61485.

git-svn-id: https://develop.svn.wordpress.org/trunk@59341 602fd350-edb4-49c9-b593-d223f7449a82

Author: SergeyBiryukov

src/wp-admin/load-styles.php

@@ -55,7 +55,7 @@
 $wp_styles = new WP_Styles();
 wp_default_styles( $wp_styles );
 
-$etag = $wp_styles->get_etag( $wp_version, $load );
+$etag = $wp_styles->get_etag( $load );
 
 if ( isset( $_SERVER['HTTP_IF_NONE_MATCH'] ) && stripslashes( $_SERVER['HTTP_IF_NONE_MATCH'] ) === $etag ) {
 	header( "$protocol 304 Not Modified" );