Bump opencv-python from 4.5.3.56 to 4.8.1.78

Bumps [opencv-python](https://github.com/opencv/opencv-python) from 4.5.3.56 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
  dependency-type: direct:production
...

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

setup.py

@@ -12,7 +12,7 @@
     packages=['barcode_reader'],
     install_requires=[
         'numpy==1.21.2',
-        'opencv-python==4.5.3.56'
+        'opencv-python==4.8.1.78'
     ],
     zip_safe=False
 )