text: Title: conda env's bin override ~/.local/bin in PATH
  Body: ### Bug description
  
  PATH in a newly build container image is: `/srv/conda/envs/notebook/bin:/srv/conda/condabin:/home/yuvipanda/.local/bin:/home/yuvipanda/.local/bin:/srv/conda/envs/notebook/bin:/srv/conda/bin:/srv/npm/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin`
  
  Note that the two conda environments - notebook and condabin - override what ${HOME}/.local/bin or ${REPO_DIR}/.local/bin. IMO this is unintentional - user bin dirs should always be able to override everything.
  
  #### Expected behaviour
  
  I can put a binary in ${HOME}/.local/bin and that is preferred over a binary in /srv/conda/envs/notebook/bin by default.
  
  #### Actual behaviour
  
  Binary in /srv/conda/envs/notebook/bin is preferred.
  
  ### How to reproduce
  
  1. Install mamba instead of conda #643 
  2. Symlink mamba to conda in ${HOME}/.local/bin
  3. During the installation / symlink process, 'conda' points to 'mamba'
  4. When container is *running*, 'conda' is back to pointing to the 'conda' in the notebook environment.