Update dependency font-awesome to v6.7.1

Author: renovate[bot]

_includes/css.html

@@ -3,7 +3,7 @@
         <link rel="stylesheet" href="//fonts.googleapis.com/css?family=Roboto:300,400,500,700" type="text/css">
 
         <!-- FontAwesome icons -->
-        <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/6.4.2/css/all.min.css">
+        <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/6.7.1/css/all.min.css">
 
         <!-- Core BootStrap CSS -->
         <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.6/css/bootstrap.min.css">