evaluation: pull --rebase before push

Author: Gerit Wagner

.github/workflows/evaluate.yml

@@ -83,4 +83,5 @@ jobs:
           git add output/*
           git add docs/_static/evaluation_total.png*
           git commit -m "Update evaluation ($(date +'%Y-%m-%d-%H-%M'))"
+          git pull origin main --rebase
           git push origin main