RTD Failing with `ModuleNotFoundError: No module named 'yaml'`

[jacobtomlinson]

Read the docs builds are failing here https://app.readthedocs.org/projects/dask-mpi/builds/30267900/

python -m pip install --upgrade --upgrade-strategy only-if-needed --no-cache-dir .  
Processing /home/docs/checkouts/readthedocs.org/user_builds/dask-mpi/checkouts/142
  Installing build dependencies: started
  Installing build dependencies: finished with status 'done'
  Getting requirements to build wheel: started
  Getting requirements to build wheel: finished with status 'error'
  error: subprocess-exited-with-error
  
  × Getting requirements to build wheel did not run successfully.
  │ exit code: 1
  ╰─> [20 lines of output]
      Traceback (most recent call last):
        File "/home/docs/checkouts/readthedocs.org/user_builds/dask-mpi/conda/142/lib/python3.11/site-packages/pip/_vendor/pyproject_hooks/_in_process/_in_process.py", line 389, in <module>
          main()
        File "/home/docs/checkouts/readthedocs.org/user_builds/dask-mpi/conda/142/lib/python3.11/site-packages/pip/_vendor/pyproject_hooks/_in_process/_in_process.py", line 373, in main
          json_out["return_val"] = hook(**hook_input["kwargs"])
                                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
        File "/home/docs/checkouts/readthedocs.org/user_builds/dask-mpi/conda/142/lib/python3.11/site-packages/pip/_vendor/pyproject_hooks/_in_process/_in_process.py", line 143, in get_requires_for_build_wheel
          return hook(config_settings)
                 ^^^^^^^^^^^^^^^^^^^^^
        File "/tmp/pip-build-env-2boq683c/overlay/lib/python3.11/site-packages/setuptools/build_meta.py", line 331, in get_requires_for_build_wheel
          return self._get_build_requires(config_settings, requirements=[])
                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
        File "/tmp/pip-build-env-2boq683c/overlay/lib/python3.11/site-packages/setuptools/build_meta.py", line 301, in _get_build_requires
          self.run_setup()
        File "/tmp/pip-build-env-2boq683c/overlay/lib/python3.11/site-packages/setuptools/build_meta.py", line 512, in run_setup
          super().run_setup(setup_script=setup_script)
        File "/tmp/pip-build-env-2boq683c/overlay/lib/python3.11/site-packages/setuptools/build_meta.py", line 317, in run_setup
          exec(code, locals())
        File "<string>", line 3, in <module>
      ModuleNotFoundError: No module named 'yaml'
      [end of output]
  
  note: This error originates from a subprocess, and is likely not a problem with pip.
ERROR: Failed to build 'file:///home/docs/checkouts/readthedocs.org/user_builds/dask-mpi/checkouts/142' when getting requirements to build wheel