F523: Single variable with single quotes triggers syntax violation

[addisoncrump]

Reproduction

The following snippet is a minimal reproduction:

x = 5
'".'.format(x)

The fix attempted:

x = 5
"".".format()

Command line

ruff check format.py --fix --isolated

Version information

Built on e82160a (latest, bleeding).

Misc

Discovered by #4822.

[charliermarsh]

Thanks!

[charliermarsh]

Looks like F523 always uses double quotes: new_format_string = format!(r#""{new_format_string}""#);