graphics/openexr*: Update to 3.4.8

Bugfix release

Changelog(s):
https://github.com/AcademySoftwareFoundation/openexr/releases/tag/v3.4.8
https://github.com/AcademySoftwareFoundation/openexr/releases/tag/v3.4.7
https://github.com/AcademySoftwareFoundation/openexr/releases/tag/v3.4.6

PR: 293859