Do not add palette entries when reading other lines

Tests/test_file_gimppalette.py

@@ -32,4 +32,4 @@ def test_get_palette() -> None:
 
     # Assert
     assert mode == "RGB"
-    assert len(palette) / 3 == 11
+    assert len(palette) / 3 == 8

src/PIL/GimpPaletteFile.py

@@ -32,14 +32,13 @@ class GimpPaletteFile:
             raise SyntaxError(msg)
 
         palette: list[int] = []
-        for i in range(256):
+        for _ in range(256):
             s = fp.readline()
             if not s:
                 break
 
             # skip fields and comment lines
             if re.match(rb"\w+:|#", s):
-                palette.append(o8(i) * 3)
                 continue
             if len(s) > 100:
                 msg = "bad palette file"