Highlights of this release

This is a bugfix release that collects a number of additional issues discovered
and fixed since the 7.4.2 release. Among the fixes, this pins PySide6 to less than
6.4.0, as 6.4 has breaking changes in it.

Thanks to:

• Alex Chabot-Leclerc
• Mark Dickinson
• Eric Larson
• Steven Kern
• Corran Webster

Detailed changes

Fixes

• Fix code editor gutter widget on recent Python versions (#1176)
• fix issues with FileDialog and DirectoryDialog close method on Linux (#1175)
• update setup.py metadata (#1173)
• restrict to PySide versions before 6.4.0 (#1169)
• don't do unneccessary evaluations of conditions in EventLoopHelper (#1168)
• fix a deleted object error in PyQt5 (#1161)
• better reporting of toolkit errors (#1157)

Documentation

• fix some Python 2 style print statements in documentation (#1157)