Fix downloader config breaking plugins with sync upload

[gerrod3]

📜 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 3.103: 💚 backport PR created

✅ Backport PR branch: patchback/backports/3.103/02fbd2f8c0af2eca82caeaf7625d132f1ea94410/pr-7276

Backported as #7277

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