Last `label: |` reformatted into `label: |-` despite new line

There is this small quirk I am having with `yamlfmt`. This file

```yaml
label: |
foo
label: |
foo
```

is reformatted into

```yaml
label: |
foo
label: |-
foo
```

despite the presence of a new line. I tried playing with `retain_line_breaks` and `eof_newline`, to no avail. Is it something I don't understand about yaml and yamlfmt is doing the right thing? Or is there an option to remove this unnecessary '-'? Or is it a quirk that is yet to be fixed? 🙏