Bump jython to support P2.7 and P3

[ArneBachmann]

Currently the integrated jython runs V2.5.1 which, e.g., doesn't support str.format() function.

[yocaba]

Reported in main issue tracker for proper scheduling. Resolution will be reported back as soon as available.

Link to issue: https://mantis.sc.dlr.de/view.php?id=15132

[rmischke-dlr]

Update on the Python/Jython situation:

Our current roadmap is to migrate away from Jython completely, using "native" Python for everything instead. While Jython may eventually reach Python 3 support, its roadmap is far to unclear to rely on this for core functionality (e.g. tool pre/post scripts).

As Python 2 is EOL, this of course includes switching all user scripts to Python 3, which may require user intervention. This is why we won't (can't) deploy this change before RCE 11.0.0.

[rmischke-dlr]

Update: The complete replacement of Jython with "native" Python 3 is mostly complete (except some fine-tuning and documentation) and has successfully passed internal testing. This change enables tool pre- and post-execution scripts with full access to native Python modules, venv support etc.

Due to our version compatibility policy, however, we still can't release this change before RCE 11.0.0.