get_proposal_pos_embed of deformable_detr support return dtype of proposal 
Author: DonggeunYu
Pull request: yes

# What does this PR do?

Currently function `get_proposal_pos_embed` is fixed with return float32.
Modified to return dtype of proposal.

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Comments:
The lint problem is with other files.

@DonggeunYu Indeed. I've tried re-running, but it doesn't appear to be using the new docker images (which it should). Could you try rebasing on main? 

> @DonggeunYu Indeed. I've tried re-running, but it doesn't appear to be using the new docker images (which it should). Could you try rebasing on main?

@amyeroberts Done.

@amyeroberts Please check this PR.

@DonggeunYu Yesterday, we deprecated DETA. Could you rebase to include this change on main here? This will resolve the repo consistency check 

> @DonggeunYu Yesterday, we deprecated DETA. Could you rebase to include this change on main here? This will resolve the repo consistency check

@amyeroberts Completed.

@DonggeunYu My bad, the # Copied froms are still active. I've opened a PR to #31153 to remove these. Once merged, we can add that in and then we won't need to worry about DETA for this PR. Thanks for your patience! 

@DonggeunYu #31153 has been merged in. It would be good to still merge in this PR! I'll reopen. If you still wish to add and work on this, then adding upstream changes from main should fix the failing tests and I can merge. Otherwise fee lfree to close again :)

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