Update Dockerfile with test virtualizarr branch

Author: abarciauskas-bgse

Dockerfile

@@ -33,5 +33,5 @@ RUN bash ${HOME}/.kernels/install-vscode-ext.sh
 RUN python -m pip install obstore==0.3.0b10
 
 # Install icechunk development packages (these steps required from https://github.com/earth-mover/icechunk/issues/197)
-RUN python -m pip install icechunk xarray VirtualiZarr
+RUN python -m pip install xarray git+https://github.com/zarr-developers/VirtualiZarr.git@ab/upgrade-icechunk#egg=VirtualiZarr[icechunk]
 RUN python -m pip install git+https://github.com/mpiannucci/kerchunk@v3