Update book.yml

Author: pnavaro

.github/workflows/book.yml

@@ -24,10 +24,7 @@ jobs:
 
     - name: Install PyCall
       shell: bash {0}
-      env:
-          PYTHON: ""
       run: |
-        julia -e ' using Pkg; Pkg.update() '
         julia -e ' using Pkg; Pkg.add(["REPL", "PyCall"]); Pkg.build("PyCall")'
 
     - name: Build the book