Bug 35295: Move JS asset in returns.tt

Bug 35295: Move JS asset in returns.tt

To Test:
1. Place a hold
2. Check-in an item of the held record
3. No hold modal 😱
4. APPLY PATCH
5. Hold modal!!!

Signed-off-by: David Nind <david@davidnind.com>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>
(cherry picked from commit 771334218acc2a5eb97bac1eab38a53543084444)
Signed-off-by: Fridolin Somers <fridolin.somers@biblibre.com>
(cherry picked from commit 6abfcbecd878bb634b129df59c345f2c80c4955f)
Signed-off-by: Pedro Amorim <pedro.amorim@ptfs-europe.com>