Copy environment.yml from correct place

Author: yuvipanda

.binder/Dockerfile

@@ -1,6 +1,6 @@
 # Inherit from an upstream image
 FROM quay.io/jupyter/base-notebook:2025-02-03
 
-COPY environment.yml /tmp/environment.yml
+COPY ./.binder/environment.yml /tmp/environment.yml
 
 RUN mamba env update  --debug --prefix ${CONDA_DIR} --file /tmp/environment.yml