Software Environment Updates

[haraldschilly]

"Default" software environment images "Ubuntu 20.04" and "Ubuntu 22.04" were updated. They now include Sage 9.8 and a rather large set of changes.

If you run into troubles, as always you can switch back to the "Previous" variant. Please let us know about the problem, such that we can fix it.

Known issues:

• 22.04/C++: library dependency issues. please use 20.04