libct: suppress strings.Title deprecation warning

Function strings.Title is deprecated as of Go 1.18, because it does not
handle some corner cases good enough. In this case, though, it is
perfectly fine to use it since we have a single ASCII word as an
argument, and strings.Title won't be removed until at least Go 2.0.

Suppress the deprecation warning.

The alternative is to not capitalize the namespace string; this will break
restoring of a container checkpointed by earlier version of runc.

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

libcontainer/container_linux.go

@@ -920,7 +920,7 @@ func (c *linuxContainer) criuSupportsExtNS(t configs.NamespaceType) bool {
 }
 
 func criuNsToKey(t configs.NamespaceType) string {
-	return "extRoot" + strings.Title(configs.NsName(t)) + "NS"
+	return "extRoot" + strings.Title(configs.NsName(t)) + "NS" //nolint:staticcheck // SA1019: strings.Title is deprecated
 }
 
 func (c *linuxContainer) handleCheckpointingExternalNamespaces(rpcOpts *criurpc.CriuOpts, t configs.NamespaceType) error {