trailingComma setting is not respected in SCSS lists/maps.

It seems that #4076 has cropped up again?

Prettier 1.15.3
Playground link

--parser scss
--trailing-comma all

Input:

$my-colors: (
  'red',
  'blue',
  'green',
  'pink',
  'orange',
  'purple',
  'magenta',
  'puce',
);

Output:

$my-colors: (
  "red",
  "blue",
  "green",
  "pink",
  "orange",
  "purple",
  "magenta",
  "puce"
);

Expected behavior:

trailingComma setting should be respected:

$my-colors: (
  "red",
  "blue",
  "green",
  "pink",
  "orange",
  "purple",
  "magenta",
  "puce",
);

Reproduce the report in the linked Prettier Playground using the SCSS parser and --trailing-comma all with the provided input. Confirm the formatter preserves the trailing comma in the SCSS list, and add or update a regression test if the relevant test location can be identified.