remove unused pybind_library. (#2034)

Internal checks caught this unused import in the BUILD file.

BUG=cleanup

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 3fc77d0..75a8dc4 100644
--- a/tensorflow/lite/micro/python/interpreter/src/BUILD
+++ b/tensorflow/lite/micro/python/interpreter/src/BUILD
@@ -1,4 +1,4 @@
-load("@pybind11_bazel//:build_defs.bzl", "pybind_extension", "pybind_library")
+load("@pybind11_bazel//:build_defs.bzl", "pybind_extension")
 load("@tflm_pip_deps//:requirements.bzl", "requirement")
 load(
     "//tensorflow/lite/micro:build_def.bzl",