build: update direct dependencies and fix serve nfs

This updates the direct dependencies.

The latest github.com/willscott/go-nfs has changed the interface
slightly so this implements a dummy InvalidateHandle method in order
to satisfy it.

cmd/serve/nfs/handler.go

@@ -63,6 +63,11 @@ func (h *BackendAuthHandler) HandleLimit() int {
 	return -1
 }
 
+// InvalidateHandle is called on removes or renames
+func (h *BackendAuthHandler) InvalidateHandle(billy.Filesystem, []byte) error {
+	return nil
+}
+
 func newHandler(vfs *vfs.VFS) nfs.Handler {
 	handler := NewBackendAuthHandler(vfs)
 	cacheHelper := nfshelper.NewCachingHandler(handler, 1024)