TensorFlow is protobuf>4 now.

This is failing with tf-nightly.

PiperOrigin-RevId: 509101102

Author: MarkDaoust

setup.py

@@ -14,7 +14,6 @@
 # ==============================================================================
 """tensorflow_docs is a package for generating python api-reference docs."""
 
-import subprocess
 import sys
 
 from setuptools import find_packages
@@ -30,14 +29,7 @@
     'absl-py',
     'jinja2',
     'nbformat',
-    # TODO(b/182876485): Protobuf 3.20 results in linker errors on Windows
-    # Protobuf 4.0 is binary incompatible with what C++ TF uses.
-    # We need ~1 quarter to update properly.
-    # See also: https://github.com/tensorflow/tensorflow/issues/53234
-    # See also: https://github.com/protocolbuffers/protobuf/issues/9954
-    # See also: https://github.com/tensorflow/tensorflow/issues/56077
-    # This is a temporary patch for now, to patch previous TF releases.
-    'protobuf >= 3.12.0, < 3.20',
+    'protobuf',
     'pyyaml',
 ]