void delopt(cli_s *cli, ...opts);
deallocates a variable amount of opt_s structs from the
cli->opts dynamic array in a cli_s struct.
see ezcli/cli_s and ezcli/opt_s for more details.
note: delopt() is a macro that inserts a sentinel
NULL after your variable amount of options. the actual
functionality lives in src/ezcli/utils/delopt.c.