Black

• Fix failure caused by fmt: skip and indentation (#2281)
• Account for += assignment when deciding whether to split string (#2312)
• Correct max string length calculation when there are string operators (#2292)
• Fixed option usage when using the --code flag (#2259)
• Do not call uvloop.install() when Black is used as a library (#2303)
• Added --required-version option to require a specific version to be running (#2300)
• Fix incorrect custom breakpoint indices when string group contains fake f-strings (#2311)
• Fix regression where R prefixes would be lowercased for docstrings (#2285)
• Fix handling of named escapes (\N{...}) when --experimental-string-processing is used (#2319)