sparkle:os seems to be ignored

[Foaly]

Hello there!

Consider the following: I have a windows application in version 0.9.0 and the following appcast.xml

<?xml version="1.0" encoding="UTF-8"?>
<rss version="2.0" xmlns:sparkle="http://www.andymatuschak.org/xml-namespaces/sparkle" xmlns:dc="http://purl.org/dc/elements/1.1/">
  <channel>
    <title>UpdaterExample Release</title>
    <description>The latest stable release of UpdaterExample.</description>
    <language>en</language>

    <item>
      <title>Version 1.0.0</title>
      <pubDate>Tue, 21 May 2024 14:31:00 +0000</pubDate>
      <enclosure sparkle:os="macos"
                 sparkle:version="1.0.0"
                 url="https://www.link.to.a.dmg"
                 length="2620494"
                 type="application/octet-stream"/>
    </item>
  </channel>
</rss>

If I run the update command WinSparkle will download and run the dmg from the macos enclosure url. I would expect is to say no new version available. This seems like a bug to me. Please let me know if I am missing anything.

Thank you for your work and this great library.