Fix test collection and mypy under zarr 3.2.x (#171)

* Fix test collection and mypy under zarr 3.2.x

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

* Add changelog fragment for #171

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

---------

Co-authored-by: Claude Fable 5 <noreply@anthropic.com>

Author: d-v-b

changes/171.bugfix.md

@@ -0,0 +1 @@
+Fixed test-suite collection (`Struct`/`Structured` dtype) and mypy type-checking under zarr-python 3.2.x.

tests/test_pydantic_zarr/conftest.py

@@ -73,6 +73,7 @@ class DTypeExample:
         Int32,
         NullTerminatedBytes,
         RawBytes,
+        Structured,
         TimeDelta64,
         data_type_registry,
     )
@@ -84,7 +85,7 @@ class DTypeExample:
             dt = dtype_cls(unit="s", scale_factor=10)
         elif dtype_cls in (FixedLengthUTF32, RawBytes, NullTerminatedBytes):
             dt = dtype_cls(length=10)
-        elif dtype_cls._zarr_v3_name in ("struct", "structured"):
+        elif issubclass(dtype_cls, Structured):
             dt = dtype_cls(fields=[("a", Int32()), ("b", Float16())])
         else:
             dt = dtype_cls()