Raise error if mpas_analysis is installed in different worktree

[xylar]

Checklist

• Testing comment in the PR documents testing used to verify the changes

[xylar]

Testing

I ran mpas_analysis --help in the "correct" directory worktree and everything works as normal. I then ran mpas_analysis --help in the "wrong" worktree and I see:

Traceback (most recent call last):
  File "/gpfs/fs1/home/ac.xylar/chrysalis/miniforge3/envs/mpas_dev/bin/mpas_analysis", line 8, in <module>
    sys.exit(main())
             ~~~~^^
  File "/gpfs/fs1/home/ac.xylar/mpas_work/MPAS-Analysis/add-wrong-worktree-error/mpas_analysis/__main__.py", line 981, in main
    but the package is installed in editable mode in a different directory.
                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    ...<6 lines>...
            description=__doc__, formatter_class=argparse.RawTextHelpFormatter)
            ^^^^^
OSError: 
The current working directory is the base of an mpas_analysis git branch,
but the package is installed in editable mode in a different directory.
Please reinstall mpas_analysis in editable mode using:
    python -m pip install --no-deps --no-build-isolation -e .

as expected.