omgidl-serialization/v1.2.1

What's Changed

• Fix sequential field id assignment by @jtbandes in #328
• bump @foxglove/omgidl-serialization to 1.2.1 by @jtbandes in #329

Full Changelog: omgidl-serialization/v1.2.0...omgidl-serialization/v1.2.1