ci: add wasm32-unknown-unknown to publish workflow as well

Author: ctron

.github/workflows/pr-preview-build.yml

@@ -6,6 +6,8 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v6
+      - run: |
+          rustup target add wasm32-unknown-unknown
 
       - name: Install trunk
         run: |