ci: add pkg-pr-new publish workflow for PR previews

Author: angelorc

.github/workflows/publish.yml

@@ -0,0 +1,16 @@
+name: publish
+on:
+  pull_request: {}
+  push:
+    branches: [next]
+jobs:
+  publish:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v6
+      - run: npm i -fg corepack && corepack enable
+      - uses: actions/setup-node@v6
+        with: { node-version: lts/*, cache: "pnpm" }
+      - run: pnpm install
+      - run: pnpm build
+      - run: pnpx pkg-pr-new publish --no-template --pnpm './packages/*'