Fix a bunch of other low-hanging style lints (#36498)

- **Fix a bunch of low hanging style lints like unnecessary-return**
- **Fix single worktree violation**
- **And the rest**

Release Notes:

- N/A

crates/agent/src/thread_store.rs

@@ -42,7 +42,7 @@ use std::{
 use util::ResultExt as _;
 
 pub static ZED_STATELESS: std::sync::LazyLock<bool> =
-    std::sync::LazyLock::new(|| std::env::var("ZED_STATELESS").map_or(false, |v| !v.is_empty()));
+    std::sync::LazyLock::new(|| std::env::var("ZED_STATELESS").is_ok_and(|v| !v.is_empty()));
 
 #[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
 pub enum DataType {