5.0.0

Bugs resolved in this release:

• bug 1767535 Drop Python 3.6 support
• bug 1782252 Upgrade to PySide6
• bug 1786362 Move windows GUI tests + builds to GitHub
• bug 1786363 Move artifact uploads to separate workflow
• bug 1786365 Generated macOS bundles are corrupt
• bug 1786367 Use Ubuntu 20.04 in CI
• bug 1785214 new mozregression 4.0.19 can't be opened at all on macOS 12
• bug 1785066 automate PyPI releases