Bump onnx in /python/OpenVINO_EP/yolov4_object_detection

Bumps [onnx](https://github.com/onnx/onnx) from 1.11.0 to 1.13.0.
- [Release notes](https://github.com/onnx/onnx/releases)
- [Changelog](https://github.com/onnx/onnx/blob/main/docs/Changelog.md)
- [Commits](onnx/onnx@v1.11.0...v1.13.0)

---
updated-dependencies:
- dependency-name: onnx
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

python/OpenVINO_EP/yolov4_object_detection/requirements.txt

@@ -1,7 +1,7 @@
 certifi==2022.5.18.1
 flatbuffers==2.0
 numpy==1.22.4
-onnx==1.11.0
+onnx==1.13.0
 opencv-python==4.5.5.64
 Pillow==9.3.0
 protobuf==4.21.6