chore: remove old filters, hardcoded types, old post status from view

src/includes/base.liquid

@@ -142,7 +142,7 @@
               "inLanguage": "{{ globals.locale }}",
               "publisher": { "@type": "{{ globals.site_type }}", "name": "{{ globals.author }}", "url": "{{ globals.url }}" },
               "author": { "@type": "Person", "name": "{{ globals.author }}" },
-              "datePublished": "{{ page.date | isoDateOnly: '.' }}"
+              "datePublished": "{{ page.date | date: "%Y.%m.%d" }}"
             }
           {%- endif -%}
         ]

src/includes/partials/blocks/banners/old-post.liquid

@@ -1,4 +1,3 @@
-{%- assign isOldPost = date | oldPost -%}
 {%- if isOldPost -%}
   <div class="banner old-post">
     <p>{% tablericon "clock-x" %}This post is over 3 years old. I've probably changed my mind since it was written and it <em>could</em> be out of date.</p>

src/pages/dynamic/music/artists/artist.html

@@ -12,7 +12,7 @@ schema: artist
   {{ artist.name }} / {{ artist.country }}
 {%- endcapture -%}
 {%- capture playLabel -%}
-  {%- if artist.totalPlays == 1 -%}
+  {%- if artist.total_plays == 1 -%}
     play
   {%- else -%}
     plays
@@ -105,8 +105,8 @@ schema: artist
     {% for album in artist.albums %}
     <tr>
       <td>{{ album.name }}</td>
-      <td>{{ album.totalPlays }}</td>
-      <td>{{ album.releaseYear }}</td>
+      <td>{{ album.total_plays }}</td>
+      <td>{{ album.release_year }}</td>
     </tr>
     {% endfor %}
   </table>

src/pages/dynamic/posts/post.html

@@ -18,7 +18,7 @@ schema: blog
     {{ post.title }}
   </h3>
   <div>
-    {% render "partials/blocks/banners/old-post.liquid", date:post.date %}
+    {% render "partials/blocks/banners/old-post.liquid", isOldPost:post.old_post %}
     {%- if post.image -%}
     <img
       srcset="