Fix overly dithered frames with low motion and very few colors

Author: kornelski

Cargo.lock

@@ -29,7 +29,7 @@ gifsicle = { version = "1.93.0", optional = true }
 clap = { version = "4.2.5", features = ["cargo"], optional = true }
 gif = { version = "0.12.0", default-features = false, features = ["std", "raii_no_panic"] }
 gif-dispose = "4.0.0"
-imagequant = "4.1.1"
+imagequant = "4.2.0"
 imgref = "1.9.4"
 lodepng = { version = "3.7.2", optional = true }
 pbr = { version = "1.1.1", optional = true }