update: Remove obsolete warning about PKG on macOS

The `.pkg` binary was replaced by a regular `.dmg` in 1.60: brave/brave-browser#32316

docs/desktop-browsers.md

@@ -253,8 +253,6 @@ Brave is built upon the Chromium web browser project, so it should feel familiar
 
 </div>
 
-**macOS users:** The download for Brave Browser from their official website is a `.pkg` installer which requires admin privileges to run (and may run other unnecessary scripts on your machine). As an alternative, you can download the latest `Brave-Browser-universal.dmg` file from their [GitHub releases](https://github.com/brave/brave-browser/releases/latest) page, which provides a traditional "drag to Applications folder" install.
-
 <div class="admonition warning" markdown>
 <p class="admonition-title">Warning</p>