Remove direct dependency on once_cell

Cargo.lock

@@ -1967,7 +1967,6 @@ dependencies = [
  "image",
  "insta",
  "keyboard-types",
- "once_cell",
  "oxipng",
  "parley",
  "pollster",

masonry_core/Cargo.toml

@@ -37,7 +37,6 @@ tree_arena.workspace = true
 smallvec.workspace = true
 tracing = { workspace = true, features = ["default"] }
 image.workspace = true
-once_cell = "1.19.0"
 serde = { version = "1.0.204", features = ["derive"] }
 serde_json = "1.0.120"
 futures-intrusive = "0.5.0"

masonry_core/src/testing/snapshot_utils.rs

@@ -10,11 +10,9 @@ use std::env;
 use std::path::PathBuf;
 use std::sync::{Arc, Mutex};
 
-use once_cell::sync::Lazy;
 use serde::Deserialize;
 
-static WORKSPACES: Lazy<Mutex<BTreeMap<String, Arc<PathBuf>>>> =
-    Lazy::new(|| Mutex::new(BTreeMap::new()));
+static WORKSPACES: Mutex<BTreeMap<String, Arc<PathBuf>>> = Mutex::new(BTreeMap::new());
 
 /// Return the cargo workspace for a manifest
 pub(crate) fn get_cargo_workspace(manifest_dir: &str) -> Arc<PathBuf> {