<!-- Please only use this template for submitting enhancement requests --> **What would you like to be added**: A probe to check that the `nfd-gc` container is in fact running **Why is this needed**: More eyes on the well-being of nfd-gc instances. Similar to https://github.com/kubernetes-sigs/node-feature-discovery/issues/1549 https://github.com/kubernetes-sigs/node-feature-discovery/issues/1550
