meson: Fix missing libseccomp dependencies

meson: Fix missing libseccomp dependencies

The builds with HAVE_SECCOMP fail on missing include paths:

FAILED: src/basic/libbasic.a.p/parse-util.c.o
cc -Isrc/basic/libbasic.a.p -Isrc/basic -I../src/basic -Isrc/boot -I../src/boot -Isrc/home -I../src/home -Isrc/shared -I../src/shared -Isrc/systemd -I../src/systemd -Isrc/journal -I../src/journal -Isrc/journal-remote -I../src/journal-remote -Isrc/nspawn -I../src/nspawn -Isrc/resolve -I../src/resolve -Isrc/timesync -I../src/timesync -I../src/time-wait-sync -Isrc/login -I../src/login -Isrc/udev -I../src/udev -Isrc/libudev -I../src/libudev -Isrc/core -I../src/core -Isrc/shutdown -I../src/shutdown -I../src/xdg-autostart-generator -I../src/libsystemd/sd-bus -I../src/libsystemd/sd-device -I../src/libsystemd/sd-event -I../src/libsystemd/sd-hwdb -I../src/libsystemd/sd-id128 -I../src/libsystemd/sd-netlink -I../src/libsystemd/sd-network -I../src/libsystemd/sd-resolve -Isrc/libsystemd-network -I../src/libsystemd-network -I. -I.. -fdiagnostics-color=always -pipe -D_FILE_OFFSET_BITS=64 -Wall -Winvalid-pch -Wextra -std=gnu99 -g -Wno-unused-parameter -Wno-missing-field-initializers -Wno-unused-result -Wno-format-signedness -Werror=undef -Wlogical-op -Wmissing-include-dirs -Wold-style-definition -Wpointer-arith -Winit-self -Wfloat-equal -Wsuggest-attribute=noreturn -Werror=missing-prototypes -Werror=implicit-function-declaration -Werror=missing-declarations -Werror=return-type -Werror=incompatible-pointer-types -Werror=format=2 -Wstrict-prototypes -Wredundant-decls -Wmissing-noreturn -Wimplicit-fallthrough=5 -Wshadow -Wendif-labels -Wstrict-aliasing=2 -Wwrite-strings -Werror=overflow -Werror=shift-count-overflow -Werror=shift-overflow=2 -Wdate-time -Wnested-externs -Wno-maybe-uninitialized -ffast-math -fno-common -fdiagnostics-show-option -fno-strict-aliasing -fvisibility=hidden -fstack-protector -fstack-protector-strong --param=ssp-buffer-size=4 -Werror=shadow -include config.h -fPIC -pthread -fvisibility=default -MD -MQ src/basic/libbasic.a.p/parse-util.c.o -MF src/basic/libbasic.a.p/parse-util.c.o.d -o src/basic/libbasic.a.p/parse-util.c.o -c ../src/basic/parse-util.c
In file included from ../src/basic/parse-util.c:20:
../src/shared/seccomp-util.h:4:10: fatal error: seccomp.h: No such file or directory
    4 | #include <seccomp.h>
      |          ^~~~~~~~~~~
compilation terminated.

FAILED: test-parse-util.p/src_test_test-parse-util.c.o
cc -Itest-parse-util.p -I. -I.. -Isrc/basic -I../src/basic -Isrc/boot -I../src/boot -Isrc/home -I../src/home -Isrc/shared -I../src/shared -Isrc/systemd -I../src/systemd -Isrc/journal -I../src/journal -Isrc/journal-remote -I../src/journal-remote -Isrc/nspawn -I../src/nspawn -Isrc/resolve -I../src/resolve -Isrc/timesync -I../src/timesync -I../src/time-wait-sync -Isrc/login -I../src/login -Isrc/udev -I../src/udev -Isrc/libudev -I../src/libudev -Isrc/core -I../src/core -Isrc/shutdown -I../src/shutdown -I../src/xdg-autostart-generator -I../src/libsystemd/sd-bus -I../src/libsystemd/sd-device -I../src/libsystemd/sd-event -I../src/libsystemd/sd-hwdb -I../src/libsystemd/sd-id128 -I../src/libsystemd/sd-netlink -I../src/libsystemd/sd-network -I../src/libsystemd/sd-resolve -Isrc/libsystemd-network -I../src/libsystemd-network -fdiagnostics-color=always -pipe -D_FILE_OFFSET_BITS=64 -Wall -Winvalid-pch -Wextra -std=gnu99 -g -Wno-unused-parameter -Wno-missing-field-initializers -Wno-unused-result -Wno-format-signedness -Werror=undef -Wlogical-op -Wmissing-include-dirs -Wold-style-definition -Wpointer-arith -Winit-self -Wfloat-equal -Wsuggest-attribute=noreturn -Werror=missing-prototypes -Werror=implicit-function-declaration -Werror=missing-declarations -Werror=return-type -Werror=incompatible-pointer-types -Werror=format=2 -Wstrict-prototypes -Wredundant-decls -Wmissing-noreturn -Wimplicit-fallthrough=5 -Wshadow -Wendif-labels -Wstrict-aliasing=2 -Wwrite-strings -Werror=overflow -Werror=shift-count-overflow -Werror=shift-overflow=2 -Wdate-time -Wnested-externs -Wno-maybe-uninitialized -ffast-math -fno-common -fdiagnostics-show-option -fno-strict-aliasing -fvisibility=hidden -fstack-protector -fstack-protector-strong --param=ssp-buffer-size=4 -Werror=shadow -include config.h -MD -MQ test-parse-util.p/src_test_test-parse-util.c.o -MF test-parse-util.p/src_test_test-parse-util.c.o.d -o test-parse-util.p/src_test_test-parse-util.c.o -c ../src/test/test-parse-util.c
In file included from ../src/test/test-parse-util.c:14:
../src/shared/seccomp-util.h:4:10: fatal error: seccomp.h: No such file or directory
    4 | #include <seccomp.h>
      |          ^~~~~~~~~~~
compilation terminated.

Add the respective deps.

Fixes: 005bfaf118 ("exec: Add kill action to system call filters")