IcoImagePlugin: raise specific exception like CurImagePlugin if no images

Tests/test_file_ico.py

@@ -229,3 +229,8 @@ def test_draw_reloaded(tmp_path):
 
     with Image.open(outfile) as im:
         assert_image_equal_tofile(im, "Tests/images/hopper_draw.ico")
+
+
+def test_empty():
+    with pytest.raises(SyntaxError, match="No images were found"):
+        IcoImagePlugin.IcoImageFile("Tests/images/no_icons.ico")

src/PIL/IcoImagePlugin.py

@@ -172,6 +172,10 @@ class IcoFile:
 
             self.entry.append(icon_header)
 
+        if not self.entry:
+            msg = "No images were found"
+            raise TypeError(msg)
+
         self.entry = sorted(self.entry, key=lambda x: x["color_depth"])
         # ICO images are usually squares
         # self.entry = sorted(self.entry, key=lambda x: x['width'])