staged csi: add comment to remember enable check later

According to spec target directory must be removed after NodeUnstage
but now mounter mock doesn't delete it during mount point cleanup.
If directory deletion is enabled then other test breaks because it
relies on previous tests leaving temoprary directories.

This will be fixed separately form this PR.

Signed-off-by: Anton Kuchin <antonkuchin@nebius.com>

cloud/blockstore/tools/csi_driver/internal/driver/node_test.go

@@ -335,6 +335,13 @@ func doTestStagedPublishUnpublishVolumeForKubevirt(t *testing.T, backend string,
  })
  require.NoError(t, err)
 
+ // TODO: enable check that target directory is deleted
+ // mock mounter should remove targetPath but if it does then TestGetVolumeStatCapabilitiesWithoutVmMode
+ // fails because it relies on other tests leaving target directory (it fails if launched alone)
+ //
+ //_, err = os.Stat(targetPath)
+ //assert.True(t, os.IsNotExist(err))
+
  if backend == "nbs" {
  nbsClient.On("StopEndpoint", ctx, &nbs.TStopEndpointRequest{
  UnixSocketPath: nbsSocketPath,