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/zed/build.rs

@@ -33,6 +33,10 @@ fn main() {
 
     // Populate git sha environment variable if git is available
     println!("cargo:rerun-if-changed=../../.git/logs/HEAD");
+    println!(
+        "cargo:rustc-env=TARGET={}",
+        std::env::var("TARGET").unwrap()
+    );
     if let Ok(output) = Command::new("git").args(["rev-parse", "HEAD"]).output() {
         if output.status.success() {
             let git_sha = String::from_utf8_lossy(&output.stdout);