V2 group read file not found error

[will-moore]

This aims to fix an issue I reported at #2412 (comment)
which is causing a lot of test failures when updating ome-zarr-py to use zarr v3 at ome/ome-zarr-py#404

TODO:

• Add unit tests and/or doctests in docstrings
• Add docstrings and API docs for any new/modified user-facing classes and functions
• New/modified features documented in docs/tutorial.rst
• Changes documented in docs/release.rst
• GitHub Actions have all passed
• Test coverage is 100% (Codecov passes)

[will-moore]

There are a lot of test failures above, but it looks like my test passed!

tests/test_v2.py .................                                       [100%]

[joshmoore]

This PR fixes about 100 failures in https://github.com/ome/ome-zarr-py/pull/404/files#diff-d51ad4cb28d657d5e09c58f40674b95273611983353ab5d7bb2049bbc6303f7b ; I've fixed the merge conflict and approved the workflows. 🤞🏽 that it goes green.

[joshmoore]

Looks like fixing the merge conflict led to:

FAILED tests/test_v2.py::test_simple_group - TypeError: LocalStore.__init__() got an unexpected keyword argument 'mode'

[will-moore]

Thanks @joshmoore. Updating my test, looks like it passes without the fix in this PR, so it seems to have been fixed elsewhere. Closing for now...