Update README.md

README.md

@@ -17,7 +17,7 @@ This repository is for the [Annif](https://annif.org) projects
 using the [KAUNO vocabulary](https://finto.fi/kauno)
 served at the [Finto AI service](https://ai.finto.fi/).
 The current models were published there 2024-05-02.
-The models have been trained on Python 3.9.18 with Annif version 1.1.0.
+The models were initially trained on Python 3.9.18 with Annif version 1.1.0, and then retrained on Python 3.9.21 with Annif version 1.3.0 for compatibility reasons.
 The configurations of the projects are in individual .cfg files in the root of
 this repository.