Preserve whitespace for Quarto cell option comments

[DavisVaughan]

Summary

Part of #6140, which is nicely summarized into 2 parts here #6140 (comment)

I saw that you all now support formatting markdown files (#22470) and can support .qmd via some user configuration (#23218, #23384, #23572).

Since ruff can now directly format a .qmd, I thought it would be nice if this bug was fixed:

With ruff.toml of:

extension = { qmd = "markdown" }

test.qmd:

This is my qmd


```{python}
#| echo: true

1 + 1
```

A call to ruff format test.qmd --preview results in

This is my qmd


```{python}
# | echo: true

1 + 1
```

Note how the special quarto code cell directive #| became # |.

Note this would diverge from black's behavior. There was a request to change this in black, but it was closed psf/black#3557. But I'm hoping that the fact that ruff can support qmds directly may make this compelling enough for ruff to diverge?

Test Plan

Added a new snapshot test file.

Note the the black compatibility file comments.py does exist already, but it did not feel appropriate to add this there.

[MichaReiser]

I have to think about this but I think i'm fine with this. Seems a popular feature justifying adding an exception. It also feels very unlikely that someone writes a comment starting with |

[DavisVaughan]

@MichaReiser thanks for giving it some consideration. I felt this could at least get some conversation going. I work with the Quarto team, so please let me know if you have any follow up questions!

[astral-sh-bot]

ruff-ecosystem results

Formatter (stable)

✅ ecosystem check detected no format changes.

Formatter (preview)

✅ ecosystem check detected no format changes.

[MichaReiser]

Thanks for proposing and implementing this change.