rpm: disable seccomp to prevent tar EPERM (Fedora 40 ppc64le on Debian)

commit 07b5d90 disabled seccomp for the
deb-builds because `chmod` failed tar was failing with an EPERM (Ubuntu
24.04 armhf on 20.04 host).

It looks like the same problem happens when running Fedora 40 on a Debian
bookworm host on ppc64le.

That issue was confirmed to be related to `fchmodat2(2)`, which is a new
syscall that's not supported on the host, and therefore gets the seccomp's
default EPERM;

    fchmodat2(AT_FDCWD, "docker", 0775, AT_SYMLINK_NOFOLLOW) = -1 EPERM (Operation not permitted)
    tar: docker: Cannot change mode to rwxrwxr-x: Operation not permitted
    tar: Exiting with failure status due to previous errors

Ultimately we need to update the libseccomp profile to use ENOSYS (see
moby ticket 42871) to allow it to degrade gracefully;

    fchmodat2(AT_FDCWD, "docker", 0775, AT_SYMLINK_NOFOLLOW) = -1 ENOSYS (Function not implemented)

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

rpm/Makefile

@@ -41,7 +41,13 @@ RPMBUILD_FLAGS?=-ba\
 
 # Additional flags may be necessary at some point
 RUN_FLAGS=
+
+# FIXME(thaJeztah): disabling seccomp to handle (ppc64le) tar "chown / chmod"
+# failing when running in a Fedora 40 container on a Debian bookworm host;
+# see https://github.com/docker/docker-ce-packaging/issues/1012 and
+# https://github.com/docker/docker-ce-packaging/pull/1006#issuecomment-2006878743
 RUN?=docker run --rm \
+	--security-opt seccomp=unconfined \
 	-e PLATFORM \
 	-v $(CURDIR)/rpmbuild/SOURCES:/root/rpmbuild/SOURCES:ro \
 	-v $(CURDIR)/rpmbuild/$@/RPMS:/root/rpmbuild/RPMS \