Take into account new indexes in guide's version selector

Fixes quarkusio/quarkus#35619

_layouts/guides.html

@@ -21,15 +21,23 @@
     <div class="guidepulldown version">
     <select id="guide-version-dropdown">
       {% for version in site.data.versions.documentation -%}
-        {% assign data_source = "guides-" | append: version | replace: '.', '-' %}
+        {% assign legacy_data_source = "guides-" | append: version | replace: '.', '-' %}
         {% assign guide_present_in_version = false %}
-        {% for item in site.data[data_source].categories -%}
+        {% for item in site.data[legacy_data_source].categories -%}
           {% for guide in item.guides -%}
             {% if guide.url == guide_url -%}
               {% assign guide_present_in_version = true %}
             {% endif -%}
           {% endfor -%}
         {% endfor -%}
+        {% assign data_source = version | replace: '.', '-' %}
+        {% for type in site.data.versioned[data_source].index.quarkus.types -%}
+          {% for guide in type[1] -%}
+            {% if guide.url == guide_url -%}
+              {% assign guide_present_in_version = true %}
+            {% endif -%}
+          {% endfor -%}
+        {% endfor -%}
         {% if guide_present_in_version or docversion == version -%}
         <option value="{{ version }}" {% if docversion == version %}selected{% endif %}>{% if version == 'latest' %}{{ site.data.versions.quarkus.version | replace_regex: "\.[0-9+]\.Final", "" }} - {% endif %}{{ version | capitalize }}{% if version == 'main' %} - SNAPSHOT{% endif %}</option>
         {% endif -%}