Remove reference to deleted theme script

Author: mudge

jekyll-assets/_includes/head.html

@@ -21,7 +21,6 @@
 <link rel="stylesheet" href="{{ site.baseurl }}/css/asciidoctor-tabs.css?ver={{ site.time | date: '%s' }}">
 <link rel="stylesheet" href="{{ site.baseurl }}/css/syntax-highlighting.css?ver={{ site.time | date: '%s' }}">
 <link rel="stylesheet" href="{{ site.baseurl }}/css/tocbot.css?ver={{ site.time | date: '%s' }}">
-<script type="text/javascript" src="{{ site.baseurl }}/scripts/theme.js?ver={{ site.time | date: '%s' }}"></script>
 <script type="text/javascript" src="{{ site.baseurl }}/scripts/tocbot.js?ver={{ site.time | date: '%s' }}"></script>
 <script type="text/javascript" src="{{ site.baseurl }}/scripts/toc.js?ver={{ site.time | date: '%s' }}"></script>
 <script async src="https://www.googletagmanager.com/gtag/js?id=G-V8TFXM3BKJ"></script>