feat: Rough proof-of-concept for patch signing

[bryanoltman]

Description

Steps for this are detailed in https://docs.google.com/document/d/1QuOG8xPyMLwGdR9XchdR4bXposO4mZN21JNCPf2LZJc/edit

[codecov]

Codecov Report

Attention: Patch coverage is 98.10127% with 6 lines in your changes are missing coverage. Please review.

Project coverage is 96.57%. Comparing base (6ab6972) to head (6b7f951).

❗ Current head 6b7f951 differs from pull request most recent head 65aacae

Please upload reports for the commit 65aacae to get more accurate results.

Files	Patch %	Lines
library/src/cache/patch_manager.rs	91.89%	6 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #152      +/-   ##
==========================================
+ Coverage   96.15%   96.57%   +0.42%     
==========================================
  Files          28       21       -7     
  Lines        3091     3157      +66     
==========================================
+ Hits         2972     3049      +77     
+ Misses        119      108      -11     

Flag	Coverage Δ
library	97.78% <98.10%> (-0.05%)	⬇️
updater_tools	?

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[eseidel]

I assume we can close this?