Content set calculation is slow

[bmbouter]

Version
All the 3.y versions

Describe the bug
The calculation of what content belongs in a repo version is slow. It happens here.

To Reproduce

1. Load a system up with lots of content, lots of repos and repo versions adding and removing content.
2. Request Pulp to display the contents of a repo version
3. Notice how it will get a lot slower with a large pulp system

Expected behavior
Run faster

Additional context
This issue was reported by other users, but I couldn't find them (either open or closed). We discussed this at a F2F developer event in Sept 2024 and the general consensus was that we should look into options.

[bmbouter]

As discussed at the pulpcore meeting today the next step is to gather some data on how long this call actually takes. The hosted Pulp install in staging is a good place to do that, so when we can the services team can look into that and report back.