Add pulpcore 3.115 compatibility

[jobselko]

📜 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

[patchback]

Backport to 2.6: 💚 backport PR created

✅ Backport PR branch: patchback/backports/2.6/09ff94749c4cb33918a2d157dcaea4d7742e9ea8/pr-514

Backported as #515

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