Simplify Python code by receiving tuple from C, as per python-pillow#8740

Author: radarhere

src/PIL/AvifImagePlugin.py

@@ -77,10 +77,9 @@ def _open(self) -> None:
         )
 
         # Get info from decoder
-        width, height, n_frames, mode, icc, exif, exif_orientation, xmp = (
+        self._size, n_frames, mode, icc, exif, exif_orientation, xmp = (
             self._decoder.get_info()
         )
-        self._size = width, height
         self.n_frames = n_frames
         self.is_animated = self.n_frames > 1
         self._mode = mode

src/_avif.c

@@ -743,7 +743,7 @@ _decoder_get_info(AvifDecoderObject *self) {
     }
 
     ret = Py_BuildValue(
-        "IIIsSSIS",
+        "(II)IsSSIS",
         image->width,
         image->height,
         decoder->imageCount,