Preserve and force single inner spaces in inline arrays `[ "a", "b" ]`

[pygarap]

Please add an option to preserve, and optionally force, exactly 1 leading space after [ and 1 trailing space before ] for inline (flow) arrays.

Example:

# desired
python: [ "3.13", "3.14" ]

# current (yamlfmt)
python: ["3.13", "3.14"]