quote: drop sq_dequote_to_argv()
The last caller went away in f9dbb64fad (config: parse more robust format in GIT_CONFIG_PARAMETERS, 2021-01-12), when we switched to using sq_dequote_step(). The "to_argv()" form is not a great interface. If you care about raw speed, then sq_dequote_step() lets you work incrementally without extra allocations. If you care about simplicity, then sq_dequote_to_strvec() puts the result in an encapsulated data structure. With sq_dequote_to_argv(), you have a data dependency on the original string but still have to remember to manually free the argv array itself (but not its elements). So it's sort of a worst-of-both-worlds middle ground. Let's get rid of it. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>