#### Preserve trailing whitespace in YAML block scalars (#19764 by @splincode)

Prettier now preserves trailing spaces, tabs, and whitespace-only lines when formatting literal and folded YAML block scalars.

```js
await prettier.format("foo: |-\n  value  \n", { parser: "yaml" });

/* Prettier stable */
// -> "foo: |-\n  value\n"

/* Prettier main */
// -> "foo: |-\n  value  \n"
//                     ^^ spaces preserved
```