hugo: remove unused shortcodes

Signed-off-by: David Karlsson <35727626+dvdksn@users.noreply.github.com>

layouts/shortcodes/build-feature-state.html

@@ -1,2 +0,0 @@
-> This feature is supported in BuildKit version `{{ .Get "buildkit_v" }}`
-> and Buildx version `{{ .Get "buildx_v" }}`.

layouts/shortcodes/siblings.html

@@ -1,13 +0,0 @@
-{{/* Links to pages in the same section that also contain this shortcode */}}
-<ul class="not-prose flex flex-wrap list-none p-0 w-full text-sm">
-  {{ range page.Parent.Pages }}
-  {{ if .HasShortcode "siblings" }}
-  <li class="p-1 first-of-type:rounded-l last-of-type:rounded-r px-2 dark:bg-gray-dark-100 hover:opacity-50{{ if eq page . }}
-          bg-blue-light-500 dark:bg-gray-dark-200
-        {{ end }}">
-    <a {{ if eq page . }} class="text-white" {{ else }} class="link !no-underline" {{ end }} href="{{ .Permalink }}">{{
-      .LinkTitle }}</a>
-  </li>
-  {{ end }}
-  {{ end }}
-</ul>