Update Dockerfile

Dockerfile

-
 ARG REGISTRY_DOMAIN="docker.io/library"
 
 FROM python:3.9.12-slim-bullseye
@@ -65,7 +64,9 @@ WORKDIR /galaxy-central
 
 COPY tool/dummy.xml /galaxy-central/tool/dummy.xml
 
-RUN planemo test --galaxy_root galaxy tool/dummy.xml \
+WORKDIR /work
+
+RUN planemo test --galaxy_root /galaxy-central/galaxy /galaxy-central/tool/dummy.xml \
     && rm -rf tool*
 
 EXPOSE 9090