opencv-python depends on vulnerable libpng15

[brammerc]

Expected behaviour

Based on issue #506, expected opencv-python==4.5.5.62 to depend on libpng16.

Actual behaviour

package dependencies for opencv-python==4.5.5.62 include libpng15, which is highly vulnerable.

Steps to reproduce

• ubuntu:20.04, python 3.8
• x86
• opencv-python==4.5.5.62

Issue submission checklist

• [x ] This is not a generic OpenCV usage question (looking for help for coding, other usage questions, homework etc.)
• [x ] I have read the README of this repository and understand that this repository provides only an automated build toolchain for OpenCV Python packages (there is no actual OpenCV code here)
• [x ] The issue is related to the build scripts in this repository, to the pre-built binaries or is a feature request (such as "please enable this additional dependency")
• [x ] I'm using the latest version of opencv-python

[asmorkalov]

Duplicate #614

[asmorkalov]

Done with releases 4.5.5.64 and 3.4.17.63.