chore: update datafusion minor version (#1297)

* Add CI check that FFI example matches datafusion version

* Update datafusion to 50.3.0

* Update example to 50.3.0

* Update examples/datafusion-ffi-example/Cargo.toml

Co-authored-by: Kevin Liu <kevinjqliu@users.noreply.github.com>

---------

Co-authored-by: Kevin Liu <kevinjqliu@users.noreply.github.com>

Author: timsaucer

.github/workflows/test.yaml

@@ -44,6 +44,18 @@ jobs:
     steps:
       - uses: actions/checkout@v5
 
+      - name: Verify example datafusion version
+        run: |
+          MAIN_VERSION=$(grep -A 1 "name = \"datafusion-common\"" Cargo.lock | grep "version = " | head -1 | sed 's/.*version = "\(.*\)"/\1/')
+          EXAMPLE_VERSION=$(grep -A 1 "name = \"datafusion-common\"" examples/datafusion-ffi-example/Cargo.lock | grep "version = " | head -1 | sed 's/.*version = "\(.*\)"/\1/')
+          echo "Main crate datafusion version: $MAIN_VERSION"
+          echo "FFI example datafusion version: $EXAMPLE_VERSION"
+          
+          if [ "$MAIN_VERSION" != "$EXAMPLE_VERSION" ]; then
+            echo "❌ Error: FFI example datafusion versions don't match!"
+            exit 1
+          fi
+
       - name: Setup Rust Toolchain
         uses: dtolnay/rust-toolchain@stable
         id: rust-toolchain