Dh apmspii 526 remove content location check from polling loop

[DominicH247]

Summary

• Routine Change
• ❗ Breaking Change
• 🤖 Operational or Infrastructure Change
• ✨ New Feature
• ⚠️ Potential issues that might be caused by this change

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Review Checklist

ℹ️ This section is to be filled in by the reviewer.

• I have reviewed the changes in this PR and they fill all or part of the acceptance criteria of the ticket, and the code is in a mergeable state.
• If there were infrastructure, operational, or build changes, I have made sure there is sufficient evidence that the changes will work.
• I have ensured the changelog has been updated by the submitter, if necessary.

[matt-mercer]

would be good to see an explicit test where only the initial content location returns a 'content-location' header too