Auto merge of #24135 - jdm:backup, r=ferjm
Auto merge of #24135 - jdm:backup, r=ferjm

Update backtrace dependency.

Perhaps this will help with the crashes during backtrace generation that some people have observed.

<!-- Reviewable:start -->
---
This change is [<img src="https://reviewable.io/review_button.svg" height="34" align="absmiddle" alt="Reviewable"/>](https://reviewable.io/reviews/servo/servo/24135)
<!-- Reviewable:end -->

KiChjang/servo,notriddle/servo,KiChjang/servo,DominoTree/servo,saneyuki/servo,KiChjang/servo,notriddle/servo,saneyuki/servo,saneyuki/servo,KiChjang/servo,splav/servo,saneyuki/servo,larsbergstrom/servo,saneyuki/servo,notriddle/servo,DominoTree/servo,larsbergstrom/servo,larsbergstrom/servo,KiChjang/servo,saneyuki/servo,notriddle/servo,larsbergstrom/servo,notriddle/servo,larsbergstrom/servo,splav/servo,saneyuki/servo,DominoTree/servo,saneyuki/servo,splav/servo,notriddle/servo,splav/servo,splav/servo,saneyuki/servo,DominoTree/servo,splav/servo,KiChjang/servo,DominoTree/servo,larsbergstrom/servo,splav/servo,DominoTree/servo,DominoTree/servo,KiChjang/servo,DominoTree/servo,notriddle/servo,DominoTree/servo,DominoTree/servo,splav/servo,KiChjang/servo,splav/servo,larsbergstrom/servo,splav/servo,KiChjang/servo,notriddle/servo,larsbergstrom/servo,notriddle/servo,larsbergstrom/servo,larsbergstrom/servo,saneyuki/servo,KiChjang/servo,notriddle/servo