Rollup merge of #115655 - notriddle:notriddle/rustdoc-fe-cleanup, r=GuillaumeGomez

rustdoc: remove unused ID `mainThemeStyle`

This was added in #47620 and used to build the URL of the theme stylesheets. It isn't used any more, because #101702 changed it so that the URL was supplied in a `<meta>` tag, which also provides the hashes of the files.

Author: matthiaskrgr

src/librustdoc/html/markdown.rs

@@ -1574,7 +1574,6 @@ fn init_id_map() -> FxHashMap<Cow<'static, str>, usize> {
     map.insert("crate-search-div".into(), 1);
     // This is the list of IDs used in HTML generated in Rust (including the ones
     // used in tera template files).
-    map.insert("mainThemeStyle".into(), 1);
     map.insert("themeStyle".into(), 1);
     map.insert("settings-menu".into(), 1);
     map.insert("help-button".into(), 1);

src/librustdoc/html/templates/page.html

@@ -15,8 +15,7 @@
     <link rel="stylesheet" {#+ #}
           href="{{static_root_path|safe}}{{files.normalize_css}}"> {# #}
     <link rel="stylesheet" {#+ #}
-          href="{{static_root_path|safe}}{{files.rustdoc_css}}" {#+ #}
-          id="mainThemeStyle"> {# #}
+          href="{{static_root_path|safe}}{{files.rustdoc_css}}"> {# #}
     {% if !layout.default_settings.is_empty() %}
     <script id="default-settings" {#+ #}
       {%~ for (k, v) in layout.default_settings ~%}