Header: Use role: none instead of presentation

https://github.com/A11yance/aria-query/blob/main/CHANGELOG.md#520 apparently decided that `presentation` should now be flagged as wrong by ember-template-lint... 🤷‍♂️

Author: Turbo87

app/components/header.hbs

@@ -1,7 +1,7 @@
 <header local-class="header {{if @hero "hero"}}">
   <div local-class="header-inner">
     <LinkTo @route="index" local-class="index-link">
-      <img src="/assets/cargo.png" role="presentation" alt="" local-class="logo">
+      <img src="/assets/cargo.png" role="none" alt="" local-class="logo">
       <h1>crates.io</h1>
     </LinkTo>