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/credentials_provider/src/credentials_provider.rs

@@ -19,7 +19,7 @@ use release_channel::ReleaseChannel;
 /// Only works in development. Setting this environment variable in other
 /// release channels is a no-op.
 static ZED_DEVELOPMENT_USE_KEYCHAIN: LazyLock<bool> = LazyLock::new(|| {
-    std::env::var("ZED_DEVELOPMENT_USE_KEYCHAIN").map_or(false, |value| !value.is_empty())
+    std::env::var("ZED_DEVELOPMENT_USE_KEYCHAIN").is_ok_and(|value| !value.is_empty())
 });
 
 /// A provider for credentials.