Feature Processor subpackage missing from sagemaker-mlops wheel

**PySDK Version**
- [ ] PySDK V2 (2.x)
- [x] PySDK V3 (3.x)

**Describe the bug**
The `feature_processor` subpackage is missing from the published `sagemaker-mlops` wheel on PyPI. The source code exists in the repository under `sagemaker-mlops/src/sagemaker/mlops/feature_store/feature_processor/`, but the built wheel does not include this directory. This makes it impossible to import `feature_processor` after installing `sagemaker-mlops[feature-processor]`.

**To reproduce**
Note, all of these steps were tested on a JupyterLab space in SageMaker AI Studio.
1. Install the sagemaker packages:
```bash
pip install sagemaker==3.5.0
pip install sagemaker-mlops==1.5.0
pip install sagemaker-mlops[feature-processor]
```
2. Restart the Python kernel.
3. Attempt to import the feature processor:
```python
from sagemaker.mlops.feature_store.feature_processor import (
feature_processor,
FeatureGroupDataSource,
)
```
4. Observe the error:
``ModuleNotFoundError: No module named 'sagemaker.mlops.feature_store.feature_processor'``
5. Confirm the directory is missing from the installed package:
```bash
ls /opt/conda/lib/python3.12/site-packages/sagemaker/mlops/feature_store/
```
Output shows no feature_processor directory:
```
__init__.py dataset_builder.py ingestion_manager_pandas.py
__pycache__ feature_definition.py inputs.py
athena_query.py feature_utils.py
```

**Expected behavior**
The `feature_processor` subpackage should be included in the published `sagemaker-mlops` wheel, and the import should work after installing `sagemaker-mlops[feature-processor]`.

**Screenshots or logs**
```
╭──────────────────────────────── Traceback (most recent call last) ────────────────────────────────╮
│ in :1 │
│ │
│ ❱ 1 from sagemaker.mlops.feature_store.feature_processor import ( │
│ 2 │ feature_processor, │
│ 3 │ FeatureGroupDataSource, │
│ 4 │ CSVDataSource, │
╰──────────────────────────────────────────────────────────────────────────────────────────────────╯
ModuleNotFoundError: No module named 'sagemaker.mlops.feature_store.feature_processor'
```

**System information**
- **SageMaker Python SDK version**: 3.5.0 (sagemaker-mlops 1.5.0)
- **Framework name (eg. PyTorch) or algorithm (eg. KMeans)**: N/A
- **Framework version**: N/A
- **Python version**: 3.12
- **CPU or GPU**: CPU
- **Custom Docker image (Y/N)**: N

**Additional context**
N/A

まず sagemaker-mlops のパッケージメタデータとビルドプロセスを調査し、次にソースディレクトリ sagemaker-mlops/src/sagemaker/mlops/feature_store/feature_processor/ とビルド済み wheel の内容を比較します。wheel をビルドし、sagemaker-mlops[feature-processor] をインストールすることで、ドキュメントに記載された feature_processor の import が可能になることを確認します。

索引モデルが issue の本文から書いたものです。