Add load() statements for Blaze-builtin Python rules/providers (#6530)

## Motivation for features / changes

This is a follow up PR for
[#6495](#6495) to add
load() statements for Blaze-builtin Python rules/providers.

More information:
[go/py-add-loads-lsc](https://goto.google.com/py-add-loads-lsc)

Author: qihach64

tensorboard/plugins/wit_redirect/BUILD

@@ -1,5 +1,7 @@
 # Description:
 # Plugin with installation instructions for dynamic interpretability plugin
+load("@rules_python//python:py_library.bzl", "py_library")
+load("@rules_python//python:py_test.bzl", "py_test")
 
 package(default_visibility = ["//tensorboard:internal"])