Use distinct user agents in agent eval and zeta-cli (#35897)

Agent eval now also uses a proper Zed version

Release Notes:

- N/A

crates/zeta_cli/build.rs

@@ -1,6 +1,6 @@
 fn main() {
     let cargo_toml =
-        std::fs::read_to_string("../zed/Cargo.toml").expect("Failed to read Cargo.toml");
+        std::fs::read_to_string("../zed/Cargo.toml").expect("Failed to read crates/zed/Cargo.toml");
     let version = cargo_toml
         .lines()
         .find(|line| line.starts_with("version = "))

crates/zeta_cli/src/headless.rs

@@ -40,7 +40,7 @@ pub fn init(cx: &mut App) -> ZetaCliAppState {
 
     // Set User-Agent so we can download language servers from GitHub
     let user_agent = format!(
-        "Zed/{} ({}; {})",
+        "Zeta CLI/{} ({}; {})",
         app_version,
         std::env::consts::OS,
         std::env::consts::ARCH