docs/environment: Use jupyterlab-myst from pypy

Version 2.0.0, with support for jlab4, released on 2023-06-23.

Author: ferdnyc

docs/environment.yml

@@ -15,7 +15,7 @@ dependencies:
   - jupyter_client
   # docs
   - docutils >=0.19
-  # - jupyterlab-myst
+  - jupyterlab-myst
   - myst-nb >=0.17,<0.18
   - pandoc
   - pydata-sphinx-theme
@@ -39,4 +39,3 @@ dependencies:
   - python-libarchive-c
   - pip:
       - jupyterlite ==0.1.0b18
-      - git+https://github.com/executablebooks/jupyterlab-myst.git@agoose77/feat-jupyterlab-v4-next