Update book.yml

Author: pnavaro

.github/workflows/book.yml

@@ -23,7 +23,6 @@ jobs:
         auto-activate-base: false
 
     - name: Install PyCall
-      shell: bash {0}
       run: |
         julia -e ' using Pkg; Pkg.add(["REPL", "PyCall"]); Pkg.build("PyCall")'