Fix dynaconf's django integration code

[pedro-psb]

Forward port of 3.115: #7892

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Thre should be no settings activity after dyanconf's instantiation.

Assisted-by: Claude (Claude Code)
(cherry picked from commit 0a06d30)

📜 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

[mdellweg]

@pedro-psb Should this be backported? (3.115 inadvertantly has it already...)

[mdellweg]

I took it in here, and it seems to be the right fix. #7873
I'm going to continue backporting to the other update-ci branches now.

[pedro-psb]

Should this be backported? (3.115 inadvertantly has it already...)

Yes