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

---------

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

crates/remote_server/build.rs

@@ -9,6 +9,10 @@ fn main() {
         "cargo:rustc-env=ZED_PKG_VERSION={}",
         zed_cargo_toml.package.unwrap().version.unwrap()
     );
+    println!(
+        "cargo:rustc-env=TARGET={}",
+        std::env::var("TARGET").unwrap()
+    );
 
     // If we're building this for nightly, we want to set the ZED_COMMIT_SHA
     if let Some(release_channel) = std::env::var("ZED_RELEASE_CHANNEL").ok() {