vendor: bump runc to v1.2.1

For one thing, this release decouples device management from
libcontainer/cgroups. You can see the result of this in a dropped
cilium/ebpf dependency (which is only needed for device management).

NOTE that due to an issue with go mod / go list,
github.com/opencontainers/runc had to be added to
hack/unwanted-dependencies.json under x/exp. This is bogus because
opencontainers/runc does not use x/exp directly, only via cilium/ebpf
dependency (which is not vendored here).

Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>

hack/unwanted-dependencies.json

@@ -216,8 +216,8 @@
       ],
       "golang.org/x/exp": [
         "github.com/antlr4-go/antlr/v4",
-        "github.com/cilium/ebpf",
         "github.com/google/cel-go",
+        "github.com/opencontainers/runc",
         "k8s.io/mount-utils"
       ],
       "google.golang.org/appengine": [