chore: CI: use setup-emsdk@v12 (#2796)

Fix for below warning in GitHub Actions.

```
Web Assembly
The following actions uses node12 which is deprecated and will be forced to run on node16: mymindstorm/setup-emsdk@v11. For more info: https://github.blog/changelog/2023-06-13-github-actions-all-actions-will-run-on-node16-instead-of-node12-by-default/
```

.github/workflows/ci.yml

@@ -216,7 +216,7 @@ jobs:
           brew install ccache tree zstd coreutils gmp
         if: matrix.os == 'macos-latest'
       - name: Setup emsdk
-        uses: mymindstorm/setup-emsdk@v11
+        uses: mymindstorm/setup-emsdk@v12
         with:
           version: 3.1.44
           actions-cache-folder: emsdk