All: bump base.css stylesheet version

Follows-up #451, to
avoid cached CSS that references font families that the current HTML
no longer loads, and are thus missing.

themes/jquery/header.php

@@ -19,7 +19,7 @@
 
 	<link rel="shortcut icon" href="<?php echo get_stylesheet_directory_uri(); ?>/i/favicon.ico">
 	<link rel="stylesheet" href="<?php echo get_template_directory_uri(); ?>/lib/typesense-minibar/typesense-minibar.css">
-	<link rel="stylesheet" href="<?php echo get_template_directory_uri(); ?>/css/base.css?v=6">
+	<link rel="stylesheet" href="<?php echo get_template_directory_uri(); ?>/css/base.css?v=7">
 	<link rel="stylesheet" href="<?php bloginfo( 'stylesheet_url' ); ?>?v=4">
 
 	<script src="https://code.jquery.com/jquery-3.7.1.min.js"></script>