change the target version to 3.11

Author: keewis

Diff for: pyproject.toml

@@ -28,7 +28,7 @@ exclude = [
     "__pycache__",
     "docs",
 ]
-target-version = "py312"
+target-version = "py311"
 
 extend-include = ["*.ipynb"]
 line-length = 100

Diff for: xarray_array_testing/tests/test_cubed.py

@@ -1,4 +1,5 @@
-from contextlib import ContextManager, nullcontext
+from contextlib import AbstractContextManager as ContextManager
+from contextlib import nullcontext
 
 import cubed
 import cubed.random