Update copyright year and release in docs/conf.py

Author: weiji14

docs/conf.py

@@ -11,9 +11,9 @@
 import cupy_xarray  # noqa: F401
 
 project = "cupy-xarray"
-copyright = "2020-2024, cupy-xarray developers"
+copyright = "2020-2026, cupy-xarray developers"
 author = "cupy-xarray developers"
-release = "v0.1.4"
+release = "v0.1.5"
 
 # -- General configuration ---------------------------------------------------
 # https://www.sphinx-doc.org/en/master/usage/configuration.html#general-configuration