publish .deb for ubuntu 26.04

[gadfort]

Hopefully this doesn't require a lot, but would it be possible to build the .deb for ubuntu 26.

[klayoutmatthias]

It does not require a lot. I will publish a Ubuntu 26 package on the next minor release.

For the master branch, you can get a build for Ubuntu 26 already here: https://www.klayout.org/downloads/master/

Matthias