New features

Console: Add Score.readFile(...) to read a data file in JS (#1337 !)
Official releases on Mac and Linux now build with an updated Harfbuzz (in a hope to solve spurious crashes that look like they have been fixed in recent versions, up to now it used Qt 5.15's bundled version which is out-of-date by a few years). Windows will follow.
Linux now has subpixel AA by default which gives much crispier fonts on the release (above is without, below is with subpixel AA):

Note that in case of a non-RGB monitor, this can be toggled through the QT_SUBPIXEL_AA_TYPE environment variable (RGB, BGR, VRGB, None...).

Fixes

Detect and disable OpenGL on llvmpipe systems, which fixes a startup crash on some Linux distros especially when running in VMs.
Fix that the tempo points could not be changed from the inspector (thanks @featherfurl for reporting !)
Fix various typos in the source code (thanks @luzpaz !)
Video: use avformat_seek_file which seems to work better than av_seek_frame to seek in video files.
Video: take start offset into account.
OSC: fix that the OSC version (1.0/1.1/Extended) was not being saved
Fix an error when changing a control after changing a time signature due to the undo/redo command not being completed.
Fix that the edit dialog would sometimes come up when trying to add a new device.
Fix a potential issue when reloading after a crash where an OSCQuery device had been created and deleted.
Fix that the Linux release was building without PortAudio and ALSA support which limited its compatibility greatly.

Also big thanks to @JoaoSvidzinski who helped find many small bugs and issue over the course of three days this week !