Remove double installation of requirements_all_ds

Dockerfile

@@ -14,7 +14,7 @@ ARG skip_ds_deps
 
 # We first copy only the requirements file, to avoid rebuilding on every file
 # change.
-COPY requirements.txt requirements_dev.txt requirements_all_ds.txt ./
+COPY requirements.txt requirements_dev.txt ./
 RUN pip install -r requirements.txt -r requirements_dev.txt
 RUN if [ "x$skip_ds_deps" = "x" ] ; then pip install -r requirements_all_ds.txt ; else echo "Skipping pip install -r requirements_all_ds.txt" ; fi