Enable zucchini mar updates

💡 Proposal

Upstream issue: https://bugzilla.mozilla.org/show_bug.cgi?id=1975960

Mozilla has recently enabled support for zucchini in the updater which promises to reduce .mar sizes by 33%. We should enable support in the Tor Browser 16.0 alpha channel after the 15.0 release cycle. One caveeat is the Windows version of the decoder requires SEH (structured exception handling) which our mingw toolchain does not support, so we will need to patch the upstream library to handle this. Linux and macOS does not have this problem.

User Story

Users will receive smaller updates when upgrading Tor Browser on desktop.

Security and Privacy Implications

Security

There shouldn't be any security implications providing zucchini-based mars are a drop-in replacement for bpatch, but things we will need to verify and check still work:

generated .mar file reproducibilitity
mar signing

Prior Art

Does this feature exist in other browsers?

Does this feature exist as an extension? If yes, which one provides this functionality?

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