chore(*): Add GHA to build with retheme flag on PRs (#2248)

* chore(*): Add GHA to build with retheme flag on PRs

* chore(*): Add empty changeset

.changeset/chilly-pens-speak.md

@@ -0,0 +1,2 @@
+---
+---

.github/workflows/ui-retheme-build.yml

@@ -0,0 +1,35 @@
+name: Build Retheme packages
+run-name: Build Retheme packages
+
+on:
+  pull_request:
+    branches:
+      - main
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}-${{ github.actor }}
+  cancel-in-progress: true
+
+jobs:
+  build-retheme:
+    runs-on: ${{ vars.RUNNER_NORMAL }}
+    timeout-minutes: ${{ fromJSON(vars.TIMEOUT_MINUTES_NORMAL) }}
+    permissions:
+      contents: write
+      pull-requests: write
+    steps:
+      - name: Checkout repo
+        uses: actions/checkout@v4
+
+      - name: Setup
+        id: config
+        uses: ./.github/actions/init
+        with:
+          turbo-signature: ${{ secrets.TURBO_REMOTE_CACHE_SIGNATURE_KEY }}
+          turbo-team: ${{ vars.TURBO_TEAM }}
+          turbo-token: ${{ secrets.TURBO_TOKEN }}
+          registry-url: "https://registry.npmjs.org"
+
+      - name: Build packages
+        run: |
+          CLERK_RETHEME=1 npx turbo build --force