Fix mypy 1.16 errors

error: Statement is unreachable  [unreachable]

Author: DimitriPapadopoulos

src/zarr/core/dtype/npy/bytes.py

@@ -120,7 +120,7 @@ def _cast_scalar_unchecked(self, data: BytesLike) -> np.bytes_:
         if isinstance(data, int):
             return self.to_native_dtype().type(str(data)[: self.length])
         else:
-            return self.to_native_dtype().type(data[: self.length])
+            return self.to_native_dtype().type(data[: self.length])  # type: ignore[unreachable]
 
     def cast_scalar(self, data: object) -> np.bytes_:
         if self._check_scalar(data):
@@ -360,7 +360,7 @@ def _check_scalar(self, data: object) -> TypeGuard[BytesLike]:
     def _cast_scalar_unchecked(self, data: BytesLike) -> bytes:
         if isinstance(data, str):
             return bytes(data, encoding="utf-8")
-        return bytes(data)
+        return bytes(data)  # type: ignore[unreachable]
 
     def cast_scalar(self, data: object) -> bytes:
         if self._check_scalar(data):

src/zarr/core/indexing.py

@@ -1308,7 +1308,7 @@ def pop_fields(selection: SelectionWithFields) -> tuple[Fields | None, Selection
     if isinstance(selection, str):
         # single field selection
         return selection, ()
-    elif not isinstance(selection, tuple):
+    elif not isinstance(selection, tuple):  # type: ignore[unreachable]
         # single selection item, no fields
         # leave selection as-is
         return None, cast("Selection", selection)