Multi dus simplify

is there any way to merge these into bigger operations?

```
%c = stablehlo.constant dense<8> : tensor
%c_0 = stablehlo.constant dense<7> : tensor
%c_1 = stablehlo.constant dense<1521> : tensor
%c_3 = stablehlo.constant dense<1520> : tensor

%c_4 = stablehlo.constant dense<0> : tensor
%c_2 = stablehlo.constant dense<5> : tensor
%c_5 = stablehlo.constant dense<1> : tensor

%62 = stablehlo.dynamic_update_slice %iterArg_16, %55, %c_4, %c_5, %c_4 : (tensor<6x1522x3056xf64>, tensor<1x1520x3056xf64>, tensor, tensor, tensor) -> tensor<6x1522x3056xf64>
%66 = stablehlo.dynamic_update_slice %62, %58, %c_2, %c_5, %c_4 : (tensor<6x1522x3056xf64>, tensor<1x1520x3056xf64>, tensor, tensor, tensor) -> tensor<6x1522x3056xf64>
%75 = stablehlo.dynamic_update_slice %66, %69, %c_5, %c_4, %c_4 : (tensor<6x1522x3056xf64>, tensor<4x1x3056xf64>, tensor, tensor, tensor) -> tensor<6x1522x3056xf64>
%78 = stablehlo.dynamic_update_slice %75, %72, %c_5, %c_1, %c_4 : (tensor<6x1522x3056xf64>, tensor<4x1x3056xf64>, tensor, tensor, tensor) -> tensor<6x1522x3056xf64>
```

The issue names no files, tests, or entry points, so begin by locating the StableHLO dynamic_update_slice simplification passes in Enzyme-JAX. Clarify which sequences are safe to merge and define completion with a regression test showing equivalent output for the example operations.

Written by the indexing model from the issue text.