Plugins: Use `<em>` instead of `<span>` for PHP annotation in `wp_plugin_update_row()`, for consistency with other instances.

Props afragen.
Fixes #46598. See #43987.

git-svn-id: https://develop.svn.wordpress.org/trunk@44980 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-admin/includes/update.php

@@ -465,7 +465,7 @@ function wp_plugin_update_row( $file, $plugin_data ) {
 					esc_attr( $response->new_version ),
 					esc_url( wp_get_update_php_url() )
 				);
-				wp_update_php_annotation( '<br><span class="description">', '</span>' );
+				wp_update_php_annotation( '<br><em>', '</em>' );
 			}
 		}