Bump opencv-contrib-python from 4.3.0.36 to 4.8.1.78

Bumps [opencv-contrib-python](https://github.com/opencv/opencv-python) from 4.3.0.36 to 4.8.1.78.
- [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

@@ -54,7 +54,7 @@ nose==1.3.7
 notebook==6.0.3
 numpy==1.18.5
 oauthlib==3.1.0
-opencv-contrib-python==4.3.0.36
+opencv-contrib-python==4.8.1.78
 opt-einsum==3.2.1
 packaging==20.4
 pandas==1.0.5