Remove update.xml — updates.xml is the canonical manifest

templateDetails.xml references updates.xml. The duplicate
update.xml is not used and causes confusion.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

update.xml

@@ -1,22 +0,0 @@
-<?xml version="1.0" encoding="utf-8"?>
-<updates>
-  <update>
-    <name>MokoCassiopeia</name>
-    <description>Moko Consulting site template based on Cassiopeia.</description>
-    <element>mokocassiopeia</element>
-    <type>template</type>
-    <version>03.09.05</version>
-    <client>site</client>
-    <tags>
-      <tag>stable</tag>
-    </tags>
-    <infourl title="MokoCassiopeia">https://github.com/mokoconsulting-tech/MokoCassiopeia/releases/tag/v03.09.04-rc</infourl>
-    <downloads>
-      <downloadurl type="full" format="zip">https://github.com/mokoconsulting-tech/MokoCassiopeia/releases/download/v03.09.04-rc/mokocassiopeia-03.09.05-rc.zip</downloadurl>
-    </downloads>
-    <sha256>fa0cd74ba37ede0dbb98256feca9a1f6f70b917b8487b778118de3d18b32074b</sha256>
-    <targetplatform name="joomla" version="(5|6)\..*" />
-    <maintainer>Moko Consulting</maintainer>
-    <maintainerurl>https://mokoconsulting.tech</maintainerurl>
-  </update>
-</updates>