v6.7.0
make yacc usage POSIX compatible
ss: add checks for bc filter support
misc: use SPDX
misc/ifstat: fix incorrect output data in json mode
lnstat: Fix deref of null in print_json() function
lnstat: use same version as iproute2
nstat: fix potential NULL deref
ss: prevent "Process" column from being printed unless requested
ssfilter: fix clang warning about conversion