added missing import

Author: prishajain1

src/maxdiffusion/models/ltx2/text_encoders/feature_extractor_ltx2.py

@@ -14,7 +14,7 @@
 limitations under the License.
 """
 
-from typing import Tuple, Union
+from typing import Optional, Tuple, Union
 import jax.numpy as jnp
 from flax import nnx
 from maxdiffusion import common_types