[pallas:triton] Do not DCE the jaxpr in the lowering pass

There isn't an obvious reason for doing DCE there, and the Mosaic TPU backend
in fact doesn't DCE.

PiperOrigin-RevId: 680530571

jax/_src/pallas/triton/lowering.py

@@ -286,10 +286,6 @@ def lower_jaxpr_to_triton_module(
     raise NotImplementedError(
         "scratch memory not implemented in the Triton backend"
     )
-  with grid_mapping.trace_env():
-    jaxpr, _ = pe.dce_jaxpr(
-        jaxpr, [True] * len(jaxpr.outvars), instantiate=True
-    )
   with _new_ir_context(), ir.Location.unknown():
     module = ir.Module.create()
     attrs = module.operation.attributes