Update opencv-contrib-python requirement from <=4.3.0.28 to <=4.8.1.78

Updates the requirements on [opencv-contrib-python](https://github.com/opencv/opencv-python) to permit the latest version.
- [Release notes](https://github.com/opencv/opencv-python/releases)
- [Commits](https://github.com/opencv/opencv-python/commits)

---
updated-dependencies:
- dependency-name: opencv-contrib-python
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

requirements.txt

@@ -11,7 +11,7 @@ motmetrics
 munch
 natsort
 numba >= 0.56.2
-opencv-contrib-python <= 4.3.0.28
+opencv-contrib-python <= 4.8.1.78
 openpyxl
 # paddlepaddle >= 2.5.0
 # paddlepaddle-gpu >= 2.5.0