cleanup: remove copts from BUILD files

PiperOrigin-RevId: 681515227
Change-Id: I25b0f32d9bf013cf882e92eb386fc8e39662a9de

Author: ericsalo

sandboxed_api/sandbox2/BUILD

@@ -855,7 +855,6 @@ cc_test(
 sapi_proto_library(
     name = "forkserver_proto",
     srcs = ["forkserver.proto"],
-    copts = sapi_platform_copts(),
     deps = [":mount_tree_proto"],
 )