Formatter: single quote style converts triple single quotes to double quotes anyway

[henryiii]

I was moving pypa/build to Ruff format in pypa/build#696, since it's a single quote package, and it was previously handed by Black + pre-commit-hook's double to single quotes option. But it turns out Ruff converts triple quoted strings to double quotes even if single quotes is selected via quote-style = "single":

def foo():
    '''
    Single quotes.
    ''''

    return '''foo''' + 'bar'

Gets turned into:

def foo():
    """
    Single quotes.
    """

    return """foo""" + 'bar'

[T-256]

dup #7615

[henryiii]

Okay, closing as dup.

[charliermarsh]

@henryiii - We ended up changing the behavior (during the alpha) such that we always use double quotes for multiline strings. Also relevant is the discussion in here (#7525) around supporting a quote-style = "preserve".