Add a test for the postgresql parameter limit workaround

[dralley]

Assisted By: Claude Code

📜 Checklist

• Commits are cleanly separated with meaningful messages (simple features and bug fixes should be squashed to one commit)
• A changelog entry or entries has been added for any significant changes
• Follows the Pulp policy on AI Usage
• (For new features) - User documentation and test coverage has been added

See: Pull Request Walkthrough

[dralley]

Will be followed up by #7803

Separate PRs in order to be able to backport independently.

[patchback]

Backport to 3.85: 💔 cherry-picking failed — conflicts found

❌ Failed to cleanly apply cd6685e on top of patchback/backports/3.85/cd6685e96f0edfc3e725f4dc1e2029fb46437e1a/pr-7801

Backporting merged PR #7801 into main

1. Ensure you have a local repo clone of your fork. Unless you cloned it
   from the upstream, this would be your origin remote.
2. Make sure you have an upstream repo added as a remote too. In these
   instructions you'll refer to it by the name upstream. If you don't
   have it, here's how you can add it:

   $ git remote add upstream https://github.com/pulp/pulpcore.git

3. Ensure you have the latest copy of upstream and prepare a branch
   that will hold the backported code:

   $ git fetch upstream
   $ git checkout -b patchback/backports/3.85/cd6685e96f0edfc3e725f4dc1e2029fb46437e1a/pr-7801 upstream/3.85

4. Now, cherry-pick PR Add a test for the postgresql parameter limit workaround #7801 contents into that branch:

   $ git cherry-pick -x cd6685e96f0edfc3e725f4dc1e2029fb46437e1a

   If it'll yell at you with something like fatal: Commit cd6685e96f0edfc3e725f4dc1e2029fb46437e1a is a merge but no -m option was given., add -m 1 as follows instead:

   $ git cherry-pick -m1 -x cd6685e96f0edfc3e725f4dc1e2029fb46437e1a

5. At this point, you'll probably encounter some merge conflicts. You must
   resolve them in to preserve the patch from PR Add a test for the postgresql parameter limit workaround #7801 as close to the
   original as possible.
6. Push this branch to your fork on GitHub:

   $ git push origin patchback/backports/3.85/cd6685e96f0edfc3e725f4dc1e2029fb46437e1a/pr-7801

7. Create a PR, ensure that the CI is green. If it's not — update it so that
   the tests and any other checks pass. This is it!
   Now relax and wait for the maintainers to process your pull request
   when they have some cycles to do reviews. Don't worry — they'll tell you if
   any improvements are necessary when the time comes!

🤖 @patchback
I'm built with octomachinery and
my source is open — https://github.com/sanitizers/patchback-github-app.

[patchback]

Backport to 3.105: 💚 backport PR created

✅ Backport PR branch: patchback/backports/3.105/cd6685e96f0edfc3e725f4dc1e2029fb46437e1a/pr-7801

Backported as #7804

🤖 @patchback
I'm built with octomachinery and
my source is open — https://github.com/sanitizers/patchback-github-app.