Remove FLATBUFFERS_COPTS from bazel BUILD (#4872)

fixes #4868

BUILD

@@ -12,11 +12,6 @@ exports_files([
     "LICENSE",
 ])
 
-FLATBUFFERS_COPTS = [
-    "-Wno-implicit-fallthrough",
-    "-linclude",
-]
-
 # Public flatc library to compile flatbuffer files at runtime.
 cc_library(
     name = "flatbuffers",
@@ -30,7 +25,6 @@ cc_library(
         "src/util.cpp",
     ],
     hdrs = [":public_headers"],
-    copts = FLATBUFFERS_COPTS,
     includes = ["include/"],
     linkstatic = 1,
 )
@@ -68,7 +62,6 @@ cc_library(
         "include/flatbuffers/flatc.h",
         ":public_headers",
     ],
-    copts = FLATBUFFERS_COPTS,
     includes = [
         "grpc/",
         "include/",
@@ -101,7 +94,6 @@ cc_binary(
         "src/idl_gen_python.cpp",
         "src/idl_gen_text.cpp",
     ],
-    copts = FLATBUFFERS_COPTS,
     includes = [
         "grpc/",
         "include/",
@@ -132,7 +124,7 @@ cc_test(
         "tests/union_vector/union_vector_generated.h",
         ":public_headers",
     ],
-    copts = FLATBUFFERS_COPTS + [
+    copts = [
         "-DFLATBUFFERS_TRACK_VERIFIER_BUFFER_SIZE",
     ],
     data = [