Add pexpect to environment.yml(#1725)

pyscriptjs/environment.yml

@@ -19,6 +19,7 @@ dependencies:
           - playwright==1.33.0
           - pytest-playwright==0.3.3
           - pytest-xdist==3.3.0
+          - pexpect
           # We need Pyodide and micropip so we can import them in our Python
           # unit tests
           - pyodide_py==0.23.2