rm celer dep from workflow

Author: mathurinm

.github/workflows/main.yml

@@ -25,7 +25,6 @@ jobs:
     - name: Install other dependencies
       run: |
         conda install rpy2 -c conda-forge
-        pip install celer
         pip install statsmodels cvxopt
         pip install git+https://github.com/jolars/sortedl1.git
         # for testing Cox estimator