chore: update zerocopy to fix vulnerability

[douglaz]

fedimint-ci-audit> Crate:     zerocopy
fedimint-ci-audit> Version:   0.7.29
fedimint-ci-audit> Title:     Some Ref methods are unsound with some type parameters
fedimint-ci-audit> Date:      2023-12-14
fedimint-ci-audit> ID:        RUSTSEC-2023-0074
fedimint-ci-audit> URL:       https://rustsec.org/advisories/RUSTSEC-2023-0074
fedimint-ci-audit> Solution:  Upgrade to >=0.2.9, <0.3.0 OR >=0.3.2, <0.4.0 OR >=0.4.1, <0.5.0 OR >=0.5.2, <0.6.0 OR >=0.6.6, <0.7.0 OR >=0.7.31

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (341e97e) 56.94% compared to head (8bb0789) 57.04%.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #3972      +/-   ##
==========================================
+ Coverage   56.94%   57.04%   +0.09%     
==========================================
  Files         193      193              
  Lines       43144    43144              
==========================================
+ Hits        24569    24610      +41     
+ Misses      18575    18534      -41     

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[fedimint-backports]

Backport failed for releases/v0.2, because it was unable to cherry-pick the commit(s).

Please cherry-pick the changes locally and resolve any conflicts.

git fetch origin releases/v0.2
git worktree add -d .worktree/backport-3972-to-releases/v0.2 origin/releases/v0.2
cd .worktree/backport-3972-to-releases/v0.2
git switch --create backport-3972-to-releases/v0.2
git cherry-pick -x 8bb0789644df61f8332fec80741bab21eb975de1