remove duplicate mkldnn_data_type (#51598)

paddle/fluid/framework/ir/op_compat_sensible_pass.cc

@@ -33,7 +33,6 @@ std::unordered_set<std::string> global_extra_attrs = {
     "use_mkldnn",
     "mkldnn_data_type",
     "use_quantizer",
-    "mkldnn_data_type",
     "use_cudnn",
     "name",
     "with_quant_attr"};

paddle/phi/api/yaml/op_compat.yaml

@@ -313,7 +313,7 @@
   backward : conv2d_grad
   extra :
     attrs : [bool is_test = false, bool use_cudnn = true, bool use_mkldnn = false, bool use_addto = false,
-             str mkldnn_data_type = "float32", bool force_fp32_output = false,
+             bool force_fp32_output = false,
              int workspace_size_MB = phi::backends::gpu::GetDefaultConvWorkspaceSizeLimitMB(), bool exhaustive_search = false]
 
 - op : conv2d_fusion