Fix publish workflow: add submodules checkout for spec tests

The CI job in publish.yml was missing submodules: true, causing
spec_compliance tests to fail because the spec submodule was absent.

Author: gvonness-apolitical

.github/workflows/publish.yml

@@ -14,6 +14,8 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v6
+        with:
+          submodules: true
 
       - name: Install Rust
         uses: dtolnay/rust-toolchain@stable