PackBitsTiffCompression: Use Slice.Fill to repeat the data

src/ImageSharp/Formats/Tiff/Compression/Decompressors/PackBitsTiffCompression.cs

@@ -73,7 +73,7 @@ namespace SixLabors.ImageSharp.Formats.Tiff.Compression.Decompressors
                     byte repeatData = compressedData[compressedOffset + 1];
                     int repeatLength = 257 - headerByte;
 
-                    ArrayCopyRepeat(repeatData, buffer, decompressedOffset, repeatLength);
+                    buffer.Slice(decompressedOffset, repeatLength).Fill(repeatData);
 
                     compressedOffset += 2;
                     decompressedOffset += repeatLength;
@@ -81,14 +81,6 @@ namespace SixLabors.ImageSharp.Formats.Tiff.Compression.Decompressors
             }
         }
 
-        private static void ArrayCopyRepeat(byte value, Span<byte> destinationArray, int destinationIndex, int length)
-        {
-            for (int i = 0; i < length; i++)
-            {
-                destinationArray[i + destinationIndex] = value;
-            }
-        }
-
         /// <inheritdoc/>
         protected override void Dispose(bool disposing) => this.compressedDataMemory?.Dispose();
     }