Removing more unused styles.

sass/navigation/breadcrumb/_breadcrumb.scss

@@ -1,29 +0,0 @@
-// Dependencies.
-@import 'components/visually-hidden/visually-hidden';
-
-// Breadcrumb navigation
-//
-// The path to the current page in the form of a list of links.
-//
-// Markup: breadcrumb.twig
-//
-// Style guide: navigation.breadcrumb
-
-.breadcrumb,
-%breadcrumb {
-  &__title {
-    @extend %visually-hidden;
-  }
-
-  &__list {
-    margin: 0;
-    padding: 0;
-  }
-
-  &__item {
-    display: inline;
-    list-style-type: none;
-    margin: 0;
-    padding: 0;
-  }
-}

sass/navigation/skip-link/_skip-link.scss

@@ -1,27 +0,0 @@
-// Skip link
-//
-// To make the link completely hidden until a user tabs to the link, combine it
-// with the `visually-hidden` component.
-//
-// :focus - Focus styling.
-//
-// Markup: skip-link.twig
-//
-// Style guide: navigation.skip-link
-
-.skip-link,
-%skip-link {
-  display: block;
-  padding: 2px 0 3px;
-  text-align: center;
-
-  &:link,
-  &:visited {
-    background-color: color(skip-link-bg);
-    color: color(skip-link);
-  }
-
-  &__wrapper {
-    margin: 0;
-  }
-}

sass/navigation/skip-link/skip-link.json

@@ -1,3 +0,0 @@
-{
-  "content": "Jump to navigation"
-}