Remove duplicate dq/q nodes

Summary: There are some duplicates in this set

Reviewed By: lucylq

Differential Revision: D50611377

fbshipit-source-id: aea4dfef53cd237adefeeb48f75fccb1f6fe2f5d

Author: cccclai

exir/passes/const_prop_pass.py

@@ -55,15 +55,11 @@ def is_const(arg) -> bool:
             return False
 
         dequant_quant_ops = {
-            torch.ops.quantized_decomposed.quantize_per_channel.default,
             torch.ops.quantized_decomposed.quantize_per_tensor.default,
-            torch.ops.quantized_decomposed.dequantize_per_channel.default,
             torch.ops.quantized_decomposed.dequantize_per_tensor.default,
             torch.ops.quantized_decomposed.quantize_per_channel.default,
             torch.ops.quantized_decomposed.dequantize_per_channel.default,
-            ops.edge.quantized_decomposed.quantize_per_channel.default,
             ops.edge.quantized_decomposed.quantize_per_tensor.default,
-            ops.edge.quantized_decomposed.dequantize_per_channel.default,
             ops.edge.quantized_decomposed.dequantize_per_tensor.default,
             ops.edge.quantized_decomposed.quantize_per_channel.default,
             ops.edge.quantized_decomposed.dequantize_per_channel.default,