feat: upgrade presage/libsignal to 0.83 (#435)

The upgraded presage library also constains a fix for linking new
devices (whisperfish/presage#333).

Author: boxdot

.github/workflows/ci.yaml

@@ -32,7 +32,7 @@ jobs:
       matrix:
         toolchain:
           - stable
-          - 1.85.1 # MSRV
+          - 1.87.0 # MSRV
     runs-on: ubuntu-latest
     steps:
       - name: system dependencies