Drop --sleep-interval from the template. We really don't want to do that
as. First, it's the default value so no use repeating that in the
template. And more importantly, the commandline flag will override
anything that will be provided in the worker config file, making it
impossible for users to specify the sleep interval (other than by
editing the template directly).
This commit makes the mount of /usr/src optional in the Helm chart, and
removes it from the kustomization. Reason is that some systems do not
have a /usr/src (such as Talos) *and* have a R/O filesystem. Since
/usr/src is optional per FHS 3.0, NFD should not assume its presence.
Signed-off-by: Jorik Jonker <jorik@kippendief.biz>
