Update version numbers for TensorFlow 2.15.1
This is missing the `setup.py` file: https://github.com/tensorflow/tensorflow/blob/6f25fb0825b1e4736de5a5848da81354e29c3472/tensorflow/tools/pip_package/setup.py#L50
Before merging this PR, please double check that it has correctly updated
`core/public/version.h`, `tools/pip_package/setup.py`, and
`tensorflow/tensorflow.bzl`. Also review the execution notes below:

```
Major: 2 -> 2
Minor: 15 -> 15
Patch: 0 -> 1

WARNING: Below are potentially instances of lingering old version string 
"2.15.0" in source directory "tensorflow/" that are not updated by this script. 
Please check them manually!
tensorflow/lite/core/c/c_api.h:150:2.15.0
tensorflow/lite/tools/versioning/runtime_version.cc:76:2.15.0
tensorflow/lite/tools/versioning/runtime_version.cc:111:2.15.0
tensorflow/lite/tools/versioning/runtime_version.cc:134:2.15.0
tensorflow/lite/tools/versioning/runtime_version.cc:141:2.15.0
tensorflow/lite/tools/versioning/runtime_version.cc:270:2.15.0
tensorflow/lite/tools/versioning/runtime_version.cc:376:2.15.0
tensorflow/lite/tools/versioning/runtime_version.cc:380:2.15.0
tensorflow/lite/tools/versioning/runtime_version.cc:433:2.15.0
tensorflow/lite/tools/versioning/runtime_version.cc:434:2.15.0
tensorflow/lite/tools/versioning/runtime_version.cc:435:2.15.0
tensorflow/lite/tools/versioning/runtime_version.cc:436:2.15.0
tensorflow/tools/pip_package/setup.py:50:2.15.0
tensorflow/tools/pip_package/setup.py:120:2.15.0
tensorflow/tools/pip_package/setup.py:121:2.15.0

WARNING: Below are potentially instances of lingering old version string 
"2.15.0" in source directory "tensorflow/" that are not updated by this script. 
Please check them manually!
tensorflow/lite/core/c/c_api.h:150:2.15.0
tensorflow/lite/tools/versioning/runtime_version.cc:76:2.15.0
tensorflow/lite/tools/versioning/runtime_version.cc:111:2.15.0
tensorflow/lite/tools/versioning/runtime_version.cc:134:2.15.0
tensorflow/lite/tools/versioning/runtime_version.cc:141:2.15.0
tensorflow/lite/tools/versioning/runtime_version.cc:270:2.15.0
tensorflow/lite/tools/versioning/runtime_version.cc:376:2.15.0
tensorflow/lite/tools/versioning/runtime_version.cc:380:2.15.0
tensorflow/lite/tools/versioning/runtime_version.cc:433:2.15.0
tensorflow/lite/tools/versioning/runtime_version.cc:434:2.15.0
tensorflow/lite/tools/versioning/runtime_version.cc:435:2.15.0
tensorflow/lite/tools/versioning/runtime_version.cc:436:2.15.0
tensorflow/tools/pip_package/setup.py:50:2.15.0
tensorflow/tools/pip_package/setup.py:120:2.15.0
tensorflow/tools/pip_package/setup.py:121:2.15.0
```