Describe the feature and motivation

Currently

• the OpenEXR of OpenCV/3rdparty is version 2.3.0
• https://github.com/AcademySoftwareFoundation/openexr is version 3.4.4

Is there a license implication or a lack of interest that prevents updating the exr support of OpenCV ?

Also, if security issues have been solved, this may help getting rid of the "OPENCV_IO_ENABLE_OPENEXR" environement variable required to enable exr at run-time.