Quick dependency fix

This is a fix for the current runtime error:
```
2023-07-19 04:31:13.468998: I tensorflow/core/util/port.cc:110] oneDNN custom operations are on. You may see slightly different numerical results due to floating-point round-off errors from different computation orders. To turn them off, set the environment variable `TF_ENABLE_ONEDNN_OPTS=0`.
2023-07-19 04:31:13.517936: I tensorflow/core/platform/cpu_feature_guard.cc:182] This TensorFlow binary is optimized to use available CPU instructions in performance-critical operations.
To enable the following instructions: AVX2 AVX512F AVX512_VNNI FMA, in other operations, rebuild TensorFlow with the appropriate compiler flags.
2023-07-19 04:31:14.833726: W tensorflow/compiler/tf2tensorrt/utils/py_utils.cc:38] TF-TRT Warning: Could not find TensorRT
Traceback (most recent call last):
File "app.py", line 2, in <module>
import keras_cv
File "/home/user/.pyenv/versions/3.8.9/lib/python3.8/site-packages/keras_cv/__init__.py", line 30, in <module>
from keras_cv import bounding_box
File "/home/user/.pyenv/versions/3.8.9/lib/python3.8/site-packages/keras_cv/bounding_box/__init__.py", line 15, in <module>
from keras_cv.bounding_box.converters import _decode_deltas_to_boxes
File "/home/user/.pyenv/versions/3.8.9/lib/python3.8/site-packages/keras_cv/bounding_box/converters.py", line 19, in <module>
from keras_cv.backend import keras
File "/home/user/.pyenv/versions/3.8.9/lib/python3.8/site-packages/keras_cv/backend/__init__.py", line 78, in <module>
from keras_cv.backend import ops # noqa: E402
File "/home/user/.pyenv/versions/3.8.9/lib/python3.8/site-packages/keras_cv/backend/ops.py", line 23, in <module>
from keras_cv.backend.tf_ops import * # noqa: F403, F401
File "/home/user/.pyenv/versions/3.8.9/lib/python3.8/site-packages/keras_cv/backend/tf_ops.py", line 14, in <module>
from keras_core.src.backend.tensorflow import * # noqa: F403, F401
ModuleNotFoundError: No module named 'keras_core'
```

requirements.txt

@@ -1,3 +1,4 @@
 keras-cv
 tensorflow
-huggingface-hub
+huggingface-hub
+keras-core