Rollup merge of #123784 - GuillaumeGomez:replace-document-write, r=notriddle

Replace `document.write` with `document.head.insertAdjacent`

From [this comment](https://github.com/rust-lang/rust/pull/123706/files#r1559864981), using `document.write` is strongly discouraged (explained on [MDN](https://developer.mozilla.org/en-US/docs/Web/API/Document/write)).

I think in this case it was mostly ok but better be on the safe side.

r? `@notriddle`

Author: matthiaskrgr

src/librustdoc/html/templates/page.html

@@ -7,8 +7,7 @@
     <meta name="description" content="{{page.description}}"> {# #}
     <title>{{page.title}}</title> {# #}
     <script>if(window.location.protocol!=="file:") {# Hack to skip preloading fonts locally - see #98769 #}
-    for(f of "{{files.source_serif_4_regular}},{{files.fira_sans_regular}},{{files.fira_sans_medium}},{{files.source_code_pro_regular}},{{files.source_code_pro_semibold}}".split(",")) {# #}
-     document.write(`<link rel="preload" as="font" type="font/woff2" crossorigin href="{{static_root_path|safe}}${f}">`) {# #}
+    document.head.insertAdjacentHTML("beforeend","{{files.source_serif_4_regular}},{{files.fira_sans_regular}},{{files.fira_sans_medium}},{{files.source_code_pro_regular}},{{files.source_code_pro_semibold}}".split(",").map(f=>`<link rel="preload" as="font" type="font/woff2" crossorigin href="{{static_root_path|safe}}${f}">`).join("")) {# #}
     </script> {# #}
     <link rel="stylesheet" {#+ #}
           href="{{static_root_path|safe}}{{files.normalize_css}}"> {# #}