scylla.spec: package the node_exporter scripts
scylla.spec: package the node_exporter scripts

This patch adds the node_exporter related files to the rpm.

Signed-off-by: Amnon Heiman <ed5fc74c4692051ad0b19749fd7cea6ec2d74b9e@scylladb.com>

duarten/scylla,scylladb/scylla,scylladb/scylla,avikivity/scylla,raphaelsc/scylla,duarten/scylla,avikivity/scylla,raphaelsc/scylla,scylladb/scylla,duarten/scylla,raphaelsc/scylla,avikivity/scylla,scylladb/scylla