Viewers are not saved properly on the main branch

[Carifio24]

Describe the bug
Something very bad that I noticed - using glue-core off of the main branch of this repository, viewers are not properly restored from a Qt session.

To Reproduce
Use the current dev version of glue, together with the newest glue-qt:

• pip install git+https://github.com/glue-viz/glue
• pip install glue-qt

Expected behavior
Viewers should be saved into the session file

Screenshots
Here's a video of this in action
https://github.com/user-attachments/assets/f353c686-ddb4-420b-9362-3729037083d4

Details:

• Operating System: Ubuntu 22.04
• Python version: Python 3.11.9
• Glue version: dev
• How you installed glue: [e.g. conda or pip]

Additional context
Note that this works fine if I use the currently released version of glue-core. I would suspect #2510 as a possible cause, but to be honest I don't have a great handle on the serialization functionality as I've never really had a need to delve into it. Pinging @astrofrog in case he has thoughts on that.

[astrofrog]

Can you try glue-core dev with glue-qt dev?

[Carifio24]

It doesn't look like glue-qt has any new commits since the last release

[Carifio24]

@astrofrog So I was using the newest release of glue-qt, which I assumed was 0.3.2 (which is up-to-date with the main branch there), but it looks like the newest version on PyPI is 0.3.1. I guess the release CI failed?

[Carifio24]

I'll close this as things do work correctly using the dev versions of both packages.