//tensorflow/python/util/protobuf:protobuf_compare_test fails with protobuf > 3.20.3
Hi @elfringham ,
I have replicated the reported test fail.The test fails with the error reported by you.

  ```
File "/home/suryanarayanay/.cache/bazel/_bazel_suryanarayanay/e93ef42332b258ebf8397106d59e39e3/execroot/org_tensorflow/bazel-out/k8-opt/bin/tensorflow/python/util/protobuf/protobuf_compare_test.runfiles/org_tensorflow/tensorflow/python/util/protobuf/compare_test.py", line 324, in testCheckInitialized
    b = copy.deepcopy(a)
  File "/home/suryanarayanay/miniconda3/envs/bazel/lib/python3.9/copy.py", line 153, in deepcopy
    y = copier(memo)
  File "/home/suryanarayanay/miniconda3/envs/bazel/lib/python3.9/site-packages/google/protobuf/message.py", line 83, in __deepcopy__
    clone.MergeFrom(self)
google.protobuf.message.EncodeError: Message compare_test.Labeled is missing required fields: required
```

Also may please refer the logs attached below.

[59931-logs.txt](https://github.com/tensorflow/tensorflow/files/11001084/59931-logs.txt)
 CC - @learning-to-play  Hi @SuryanarayanaY, Please feel free to add @vam-google for protobuf related issues.
<details><summary>Click to expand!</summary> 
 
 ### Issue Type

Bug

### Have you reproduced the bug with TF nightly?

Yes

### Source

source

### Tensorflow Version

git HEAD

### Custom Code

No

### OS Platform and Distribution

Ubuntu 20.04

### Mobile device

n/a

### Python version

3.9.16

### Bazel version

5.3.0

### GCC/Compiler version

9.4.0

### CUDA/cuDNN version

n/a

### GPU model and memory

n/a

### Current Behaviour?

```shell
The test fails
```


### Standalone code to reproduce the issue

```shell
bazel test --test_timeout=300,500,-1,-1 --flaky_test_attempts=3 --test_output=all --cache_test_results=no --noremote_accept_cached --test_env=TF_ENABLE_ONEDNN_OPTS=1 --build_tag_filters=-no_oss,-oss_serial,-gpu,-tpu,-benchmark-test,-v1only,-requires-gpu --test_tag_filters=-no_oss,-oss_serial,-gpu,-tpu,-benchmark-test,-v1only,-requires-gpu --verbose_failures --build_tests_only --jobs=16 -- //tensorflow/python/util/protobuf:protobuf_compare_test
```


### Relevant log output

```shell
ERROR: testCheckInitialized (__main__.AssertTest)
AssertTest.testCheckInitialized
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/root/.cache/bazel/_bazel_root/e953b164f58eb4c9598ad736d787ff39/execroot/org_tensorflow/bazel-out/k8-opt/bin/tensorflow/python/util/protobuf/protobuf_compare_test.runfiles/org_tensorflow/tensorflow/python/util/protobuf/compare_test.py", line 324, in testCheckInitialized
    b = copy.deepcopy(a)
  File "/usr/lib/python3.9/copy.py", line 153, in deepcopy
    y = copier(memo)
  File "/usr/local/lib/python3.9/dist-packages/google/protobuf/message.py", line 83, in __deepcopy__
    clone.MergeFrom(self)
google.protobuf.message.EncodeError: Message compare_test.Labeled is missing required fields: required
```
</details>