Bump opencv-python-headless from 4.8.0.76 to 4.8.1.78

Bumps [opencv-python-headless](https://github.com/opencv/opencv-python) from 4.8.0.76 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-python-headless
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

requirements.txt

@@ -43,7 +43,7 @@ telegraph==2.2.0
 motor
 pymongo[srv]==4.5.0
 odmantic==0.9.2
-opencv-python-headless==4.8.0.76
+opencv-python-headless==4.8.1.78
 pykeyboard==0.1.5
 wget==3.2
 wikipedia==1.4.0