Fix store creation with latest zarr-python v3 (#644)

* Pin most recent beta release of zarr python

* Fix store creation

.github/workflows/ci.yaml

@@ -78,7 +78,7 @@ jobs:
         run: |
           conda activate env
           # TODO: remove --pre option when zarr v3 is out
-          python -m pip install --pre zarr
+          python -m pip install --pre zarr>=3.0.0b2
 
       # This is used to test with zfpy, which does not yet support numpy 2.0
       - name: Install older numpy and zfpy

.pre-commit-config.yaml

@@ -31,4 +31,4 @@ repos:
       hooks:
       -   id: mypy
           args: [--config-file, pyproject.toml]
-          additional_dependencies: [numpy, pytest, zfpy, 'zarr==3.0.0b1']
+          additional_dependencies: [numpy, pytest, zfpy, 'zarr>=3.0.0b2']

.readthedocs.yaml

@@ -9,7 +9,7 @@ build:
     python: "3.12"
   jobs:
     post_install:
-      - python -m pip install --pre 'zarr'
+      - python -m pip install --pre 'zarr>=3.0.0b2'
 
 sphinx:
   configuration: docs/conf.py

numcodecs/tests/test_zarr3.py

@@ -36,7 +36,7 @@
 
 @pytest.fixture
 def store() -> StorePath:
-    return StorePath(MemoryStore(mode="w"))
+    return StorePath(MemoryStore(read_only=False))
 
 
 ALL_CODECS = [getattr(numcodecs.zarr3, cls_name) for cls_name in numcodecs.zarr3.__all__]