update flatty dep

pixie.nimble

@@ -9,11 +9,10 @@ requires "nim >= 1.4.8"
 requires "vmath >= 1.1.4"
 requires "chroma >= 0.2.5"
 requires "zippy >= 0.9.11"
-requires "flatty >= 0.3.3"
+requires "flatty >= 0.3.4"
 requires "nimsimd >= 1.0.0"
 requires "bumpy >= 1.1.1"
 
-
 task bindings, "Generate bindings":
 
   proc compile(libName: string, flags = "") =

src/pixie/fileformats/png.nim

@@ -268,7 +268,6 @@ proc decodeImageData(
           result[i].a = 0
     else:
       # While we can read an extra byte safely, do so. Much faster.
-      # var rgba: ColorRGBA
       for i in 0 ..< header.height * header.width - 1:
         copyMem(result[i].addr, unfiltered[i * 3].unsafeAddr, 4)
         result[i].a = 255