Improve Linux panic reporting (#22202)

- [x] Upload separate debug symbols for Linux binaries to DigitalOcean
- [x] Send raw offsets with panic report JSON on Linux
- [x] Update `symbolicate` script to handle Linux crashes
- [x] Demangle backtraces 🎉 
- [x] Check that it works
- [x] Improve deduplication (?)
 
Release Notes:

- N/A

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Co-authored-by: Conrad <conrad@zed.dev>