second try at trying to fix RTD; (#13909)

docs/environment.yml

@@ -1,17 +1,18 b''
 name: ipython_docs
 channels:
  - conda-forge
  - defaults
 dependencies:
-  - python=3.11
-  - setuptools>=18.5
+  - python=3.10
+  - setuptools
   - sphinx>=4.2
-  - sphinx_rtd_theme>=1.0
+  - sphinx_rtd_theme
   - numpy
   - testpath
   - matplotlib
+  - pip
   - pip:
     - docrepr
     - prompt_toolkit
     - ipykernel
     - stack_data