Allow to set qBittorrent as default program

Register qBittorrent as possible default program for .torrent files and
magnet links during install.

PR #19446.

src/base/utils/os.h

@@ -40,11 +40,4 @@ namespace Utils::OS
     bool isMagnetLinkAssocSet();
     void setMagnetLinkAssoc();
 #endif // Q_OS_MACOS
-
-#ifdef Q_OS_WIN
-    bool isTorrentFileAssocSet();
-    void setTorrentFileAssoc(bool set);
-    bool isMagnetLinkAssocSet();
-    void setMagnetLinkAssoc(bool set);
-#endif // Q_OS_WIN
 }