Envisage 7.0.4

This is a bugfix release.

Fixes

• Fix a situation where preferences were incorrectly written by
  the PreferencesPane before changes were approved. (#583)
• Add a name attribute to the EventManagerPlugin. (#571)

Build

• Update copyright header end years for 2024, 2025. (#572, #589)
• Add dependendabot config for GitHub Actions; bump individual
  actions to their latest versions. (#573, #575, #576, #577, #579, #581, #588)
• Remove Slack notifications, which were using an outdated
  and unmaintained GitHub Action. (#580)
• Require apptools 5.3 or later and Python 3.8 or later. (#584)
• Update black to version 24.3.0 to address a ReDoS
  vulnerability in earlier versions. (#585)

Tests

• Remove skip decorator on some PySide6-related tests. (#587)

Documentation

• Remove the sphinx.ext.githubpages extension. (#566)