No longer sync TfLite OpResolver from upstream. (#2145)

With #1818, TFLM does not need the TfLite OpResolver.

BUG=http://b/272808609

ci/tflite_files.txt

@@ -5,7 +5,6 @@ tensorflow/lite/builtin_ops.h
 tensorflow/lite/context_util.h
 tensorflow/lite/core/api/error_reporter.cc
 tensorflow/lite/core/api/flatbuffer_conversions.cc
-tensorflow/lite/core/api/op_resolver.cc
 tensorflow/lite/core/api/tensor_utils.cc
 tensorflow/lite/core/c/common.cc
 tensorflow/lite/kernels/internal/common.cc
@@ -19,7 +18,6 @@ tensorflow/lite/c/c_api_types.h
 tensorflow/lite/c/common.h
 tensorflow/lite/core/api/error_reporter.h
 tensorflow/lite/core/api/flatbuffer_conversions.h
-tensorflow/lite/core/api/op_resolver.h
 tensorflow/lite/core/api/tensor_utils.h
 tensorflow/lite/core/c/builtin_op_data.h
 tensorflow/lite/core/c/c_api_types.h

tensorflow/lite/core/api/BUILD

@@ -15,14 +15,12 @@ cc_library(
     hdrs = [
         "error_reporter.h",
         "flatbuffer_conversions.h",
-        "op_resolver.h",
         "tensor_utils.h",
     ],
     copts = tflite_copts() + micro_copts(),
     visibility = ["//visibility:public"],
     deps = [
         ":error_reporter",
-        ":op_resolver",
         "//tensorflow/lite/c:common",
         "//tensorflow/lite/kernels/internal:compatibility",
         "//tensorflow/lite/schema:schema_fbs",
@@ -31,29 +29,10 @@ cc_library(
     ],
 )
 
-# We define separate targets for "op_resolver" and "error_reporter",
-# even though those headers are also exported by the "api" target,
-# so that targets which only want to depend on these small abstract base
-# class modules can express more fine-grained dependencies without
-# pulling in tensor_utils and flatbuffer_conversions.
-
-cc_library(
-    name = "op_resolver",
-    srcs = ["op_resolver.cc"],
-    hdrs = ["op_resolver.h"],
-    copts = tflite_copts() + micro_copts(),
-    visibility = [
-        "//visibility:public",
-    ],
-    deps = [
-        ":error_reporter",
-        "//tensorflow/lite/c:common",
-        "//tensorflow/lite/schema:schema_fbs",
-        "//tensorflow/lite/schema:schema_utils",
-        "@flatbuffers//:runtime_cc",
-    ],
-)
-
+# We define separate targets for "error_reporter", even though those headers are
+# also exported by the "api" target, so that targets which only want to depend
+# on these small abstract base class modules can express more fine-grained
+# dependencies without pulling in tensor_utils and flatbuffer_conversions.
 cc_library(
     name = "error_reporter",
     srcs = ["error_reporter.cc"],