Revert "[Executorch] optimized sigmoid"

This reverts commit 5b4d9bb. Attempting to debug/fix #7019.

Author: swolchok

kernels/optimized/cpu/op_sigmoid.cpp

@@ -25,7 +25,6 @@ _OPTIMIZED_ATEN_OPS = (
         ],
     ),
     op_target(name = "op_exp"),
-    op_target(name = "op_sigmoid"),
     op_target(
         name = "op_gelu",
         deps = select({

kernels/optimized/cpu/targets.bzl

@@ -35,11 +35,6 @@
     - arg_meta: null
       kernel_name: torch::executor::opt_exp_out
 
-- op: sigmoid.out
-  kernels:
-    - arg_meta: null
-      kernel_name: torch::executor::opt_sigmoid_out
-
 - op: le.Scalar_out
   kernels:
     - arg_meta: null

kernels/optimized/optimized-oss.yaml

@@ -37,11 +37,6 @@
     - arg_meta: null
       kernel_name: torch::executor::opt_exp_out
 
-- op: sigmoid.out
-  kernels:
-    - arg_meta: null
-      kernel_name: torch::executor::opt_sigmoid_out
-
 - op: gelu.out
   kernels:
     - arg_meta: null

kernels/optimized/optimized.yaml

@@ -297,7 +297,7 @@ def define_common_targets():
     _common_op_test("op_scatter_add_test", ["aten", "portable"])
     _common_op_test("op_select_scatter_test", ["aten", "portable"])
     _common_op_test("op_select_copy_test", ["aten", "portable"])
-    _common_op_test("op_sigmoid_test", ["aten", "portable", "optimized"])
+    _common_op_test("op_sigmoid_test", ["aten", "portable"])
     _common_op_test("op_sign_test", ["aten", "portable"])
     _common_op_test("op_sin_test", ["aten", "portable"])
     _common_op_test("op_sinh_test", ["aten", "portable"])