Update requirements.txt with tf-cpu and tf-aarch64 (#8807)

requirements.txt

@@ -29,7 +29,7 @@ seaborn>=0.11.0
 # nvidia-pyindex  # TensorRT export
 # nvidia-tensorrt  # TensorRT export
 # scikit-learn==0.19.2  # CoreML quantization
-# tensorflow>=2.4.1  # TFLite export
+# tensorflow>=2.4.1  # TFLite export (or tensorflow-cpu, tensorflow-aarch64)
 # tensorflowjs>=3.9.0  # TF.js export
 # openvino-dev  # OpenVINO export