✨ Add Python 3.13 support and update dependencies

Extends Python version support to include 3.13 in CI workflows,
tox environments, and documentation. Updates dependencies to
ensure compatibility with the new Python version and resolves
legacy workarounds for macOS GitHub Actions runners.

Upgrades include:
- `pyside6` to version 6.9.1
- `click` to version 8.2.1
- Other relevant dependency updates for compatibility.

Re-enables `pyupgrade` pre-commit hook targeting Python 3.12+.

Fixed binary creation for Intel macOS.

Makefile

@@ -97,4 +97,14 @@ gui-macos-dmg: gui ## Package GUI in a *.dmg file
                 "$(app_path_dist)/$(APP_NAME).dmg" \
                 "$(app_path_dist)/$(DMG_NAME)/"
 
+.PHONY: gui-macos-dmg-intel
+gui-macos-dmg-intel: gui ## Package GUI in a *.dmg file; Workaround for Intel Macs, since Apple Script permissions are not set correctly on GitHub Actiion Runner images
+	@poetry run mkdir -p $(app_path_dist)/dmg
+	@poetry run mv "$(app_path_dist)/$(APP_BUNDLE_NAME).app" "$(app_path_dist)/$(DMG_NAME)/$(APP_NAME).app"
+	@poetry run hdiutil create -volname "$(APP_NAME)" \
+				-srcfolder "$(app_path_dist)/$(DMG_NAME)/" \
+				-ov -format UDZO \
+				-fs APFS \
+				"$(app_path_dist)/$(APP_NAME).dmg"
+
 .DEFAULT_GOAL := help