Fix failing publish step (tailwindlabs#14060)

One of the (private) packages was missing a version which caused `pnpm
publish` to fail. This PR adds the missing version.

Author: RobinMalfait

packages/test-utils/package.json

@@ -1,5 +1,6 @@
 {
   "name": "tailwindcss-test-utils",
+  "version": "0.0.0",
   "private": true,
   "main": "index.js"
 }

scripts/version-packages.mjs

@@ -63,6 +63,7 @@ exec('pnpm --silent --filter=!./playgrounds/* -r exec pwd', async (err, stdout)
   // Track all the workspaces
   for (let path of paths) {
     let pkg = await fs.readFile(path, 'utf8').then(JSON.parse)
+    if (pkg.private) continue
     workspaces.set(pkg.name, { version: pkg.version ?? '', path })
   }