Remove unused BUILD load (#2397)

BUG=[318738218](https://b.corp.google.com/issues/318738218)

tensorflow/lite/micro/python/interpreter/src/BUILD

diff --git a/tensorflow/lite/micro/python/interpreter/src/BUILD b/tensorflow/lite/micro/python/interpreter/src/BUILD
index dc01c67..f8be0ed 100644
--- a/tensorflow/lite/micro/python/interpreter/src/BUILD
+++ b/tensorflow/lite/micro/python/interpreter/src/BUILD
@@ -1,4 +1,3 @@
-load("@rules_python//python:defs.bzl", "py_library")
 load(
     "//tensorflow/lite/micro:build_def.bzl",
     "micro_copts",