Thanks @Retired_mod, for reference if anybody finds this, the DLT release docs are here: https://docs.databricks.com/en/release-notes/delta-live-tables/index.html
This shows which versions are running for CURRENT and PREVIEW channels. In this case, was running on CURRENT channel (Spark 3.3.2), so PREVIEW channel (Spark 3.5.0) should work for the latest PySpark functions.