Remove QImageIOHandler::name()

It has been marked obsolete for a very long time, and deprecated
in code since f9e6f8efda350689211286db9154677924df8aab.

Change-Id: Ib351025369584bf3b8a3a17f980a567d2b9556ca
Reviewed-by: Jan Arve Sæther <jan-arve.saether@qt.io>

src/gui/image/qimageiohandler.cpp

@@ -416,17 +416,6 @@ QByteArray QImageIOHandler::format() const
     \sa read(), QIODevice::peek()
 */
 
-/*!
-    \obsolete
-
-    Use format() instead.
-*/
-
-QByteArray QImageIOHandler::name() const // ### Qt6: remove
-{
-    return format();
-}
-
 /*!
     Writes the image \a image to the assigned device. Returns \c true on
     success; otherwise returns \c false.

src/gui/image/qimageiohandler.h

@@ -69,9 +69,6 @@ public:
     void setFormat(const QByteArray &format) const;
     QByteArray format() const;
 
-    QT_DEPRECATED_X("Use QImageIOHandler::format() instead")
-    virtual QByteArray name() const;
-
     virtual bool canRead() const = 0;
     virtual bool read(QImage *image) = 0;
     virtual bool write(const QImage &image);