Latest python images use Trixie debian release

We've started to see various errors pop up because the python images we're using are now built on the new debian stable release, trixie. The first was that the gcc version on trixie, gcc 14, was failing to build ligo-segments and python-ligo-lw, which we're only building because of #981. After fixing that, I discovered that nagios unit test is failing due to the image using redis 8 instead of redis 7 like we do on the cluster.

I think the easiest fix for now is to use the images we were using before, which were bookworm. But I want to keep this issue open until we decide what to do longterm.