[docker] fix image path

Author: ABandet

.github/workflows/build-docker-image.yaml

@@ -31,6 +31,6 @@ jobs:
         with:
           context: .
           push: true
-          tags: ghcr.io/${{ github.repository }}/funtides-env:latest
+          tags: ghcr.io/${{ github.repository | downcase }}/funtides-env:latest
           cache-from: type=gha
           cache-to: type=gha,mode=max