queries(python): always mark kwarg names as @variable.parameter

[m4rch3n1ng]

and don't mark them as @local.reference

before:

after:

(using the onedark theme, which highlights @variable.parameter as red)

i was unsure of whether to mark kwarg arg names as parameters or as variables, so i did what neovim does, which is mark it as @variable.parameter.

resolves: #14323