fix: do not try to apply treemending patch twice

src/monaco-treemending.ts

@@ -22,8 +22,15 @@ async function run () {
     process.exit(1)
   }
 
+  const alreadyPatched: boolean = monacoPackageJson.treemended ?? false
+  if (alreadyPatched) {
+    // eslint-disable-next-line no-console
+    console.info('Monaco-editor has already been tree-mended, ignoring')
+    process.exit(0)
+  }
+
   function getMonacoFile (diff: ParsedDiff) {
-    return path.resolve(monacoDirectory, diff.oldFileName!.slice('a/'.length))
+    return path.resolve(monacoEsmDirectory, diff.oldFileName!.slice('a/'.length))
   }
 
   await new Promise<void>((resolve, reject) => {
@@ -59,11 +66,19 @@ async function run () {
       }
     })
   })
-}
 
-run().then(() => {
+  // Mark monaco as treemended
+  await fs.writeFile(monacoPackageJsonFile, JSON.stringify({
+    ...monacoPackageJson,
+    treemended: true
+  }, null, 2))
+
   // eslint-disable-next-line no-console
   console.info('Monaco-editor was tree-mended')
-}, err => {
+  process.exit(0)
+}
+
+run().catch(err => {
   console.error(err)
+  process.exit(1)
 })