community/opencascade: upgrade to 7.8.0
https://github.com/Open-Cascade-SAS/OCCT/releases/tag/V7_8_0
- building against ffmpeg is still broken and, hence, remains disabled
- detecting (One)TBB is broken and disabled for now
https://github.com/Open-Cascade-SAS/OCCT/releases/tag/V7_8_0