Removed defer attribute from the avo.base.css stylesheet tag (#3635)

`defer` isn't a valid attribute for a `<link>` tag - it is for
`<script>` tags and having it here is invalid html. I think this is also
causing loading issues in google chrome for me when I redirect from avo
to my main app.

I've removed defer from the `<link>` tag. This should make the html
valid and shouldn't have any bad effects (as it shouldn't be used on a
`<link>` tag anyway).

app/views/layouts/avo/application.html.erb

@@ -13,7 +13,7 @@
     <%= render partial: "avo/partials/branding" %>
     <%= render partial: "avo/partials/pre_head" %>
     <%= render Avo::AssetManager::StylesheetComponent.new asset_manager: Avo.asset_manager %>
-    <%= stylesheet_link_tag @stylesheet_assets_path, "data-turbo-track": "reload", defer: true, as: "style" %>
+    <%= stylesheet_link_tag @stylesheet_assets_path, "data-turbo-track": "reload", as: "style" %>
 
     <% path = Avo::PACKED ? "/avo-assets/avo.base" : "avo.base" %>
     <%= javascript_include_tag path, "data-turbo-track": "reload", defer: true %>