webview: remove KaTeX js file

Although the installation directions just say to include
katex.[min.]js unconditionally, the KaTeX JavaScript isn't actually
needed just to display existing KaTeX blocks -- only to render new
ones.

Which is good, because that's ~242K of (uncompressed) JS code that we
can do without.

src/webview/css/css.js

@@ -68,7 +68,6 @@ const katexFraclineHackStyle = `<style id="katex-frac-line-hack">
 export default (theme: ThemeName) => `
 <link rel='stylesheet' type='text/css' href='./base.css'>
 <link rel='stylesheet' type='text/css' href='./katex/katex.min.css'>
-<script defer src="./katex/katex.min.js"></script>
 <style>
 ${theme === 'night' ? cssNight : ''}
 ${cssPygments(theme === 'night')}

tools/build-webview.d/katex.all.pre

@@ -9,9 +9,8 @@ readonly _dest="${STAGING}/katex"
 readonly _katex_font_type=woff2
 
 z_rsync "${_src}/" "${_dest}" <<EOF
-# Include these two files.
+# Include the KaTeX CSS.
 +/ katex.min.css
-+/ katex.min.js
 
 # Include the fonts/ directory, and specifically those files within it
 # with the right extension.