[eclipse-uprotocol#230] Recurse submodules when checking out repo

The workflow for checking if the code can be compiled using the
latest versions of 3rd party dependencies had failed sporadically
because the uProtocol API proto3 files had not been available.

This was due to the fact that the up-spec submodule had not been
properly initialized during checkout.

Author: sophokles73

.github/workflows/verify-latest-deps.yaml

@@ -33,6 +33,8 @@ jobs:
       CARGO_RESOLVER_INCOMPATIBLE_RUST_VERSIONS: allow
     steps:
     - uses: actions/checkout@v4
+      with:
+        submodules: "recursive"
     - run: rustup update stable && rustup default stable
     - run: cargo update --verbose
     - run: cargo build --verbose --all-features