About ITK 6.0 Beta 1

[thewtex]

I plan an ITK 6.0 Alpha 3 release to facilitate testing. This will comprise basic release components, i.e. we will point to the Migration Guide, but other documentation will not be generated.

Release checklist and status:

• [ ] Check dashboard and CI
• [ ] Tag the ITK repository
• [x] Bump ITK's version
• [ ] Bump the ITKPythonPackage version
• [ ] Generate InsightToolkit and InsightData tarballs
• [ ] Archive testing data
• [ ] Write release notes
• [ ] Generate Python packages and ITKPythonBuilds
• [ ] Upload Python packages to PyPI
• [ ] Post on Discourse

Note: issues were discovered with ITK 6.0 Alpha 3, which was only partially released.