fix: prevent Yoga init from running more than once (#2878)

Author: jmezzacappa

.changeset/slow-ravens-type.md

@@ -0,0 +1,5 @@
+---
+"@react-pdf/layout": patch
+---
+
+Prevent Yoga init from running more than once

packages/layout/src/yoga/index.js

@@ -2,14 +2,12 @@
 
 import { loadYoga as yogaLoadYoga } from 'yoga-layout/load';
 
-let instance;
+let instancePromise;
 
 export const loadYoga = async () => {
-  if (!instance) {
-    // Yoga WASM binaries must be asynchronously compiled and loaded
-    // to prevent Event emitter memory leak warnings, Yoga must be loaded only once
-    instance = await yogaLoadYoga();
-  }
+  // Yoga WASM binaries must be asynchronously compiled and loaded
+  // to prevent Event emitter memory leak warnings, Yoga must be loaded only once
+  const instance = await (instancePromise ??= yogaLoadYoga());
 
   const config = instance.Config.create();