Ignore `.ipynb_checkpoints` when building docs (#13929)

This is a small thing - when editing the docs from JupyterLab Desktop,
any file opened will leave `.ipynb_checkpoints` temp directory. Editing
documentation in Jupyter itself is quite common especially when using
spinx-myst and it is convenient enough for me, but without this change
Sphinx errors out on every other build.

docs/source/conf.py

@@ -183,8 +183,7 b" today_fmt = '%B %d, %Y'"
 
 # Exclude these glob-style patterns when looking for source files. They are
 # relative to the source/ directory.
-exclude_patterns = []
-
+exclude_patterns = ["**.ipynb_checkpoints"]
 
 # If true, '()' will be appended to :func: etc. cross-reference text.
 #add_function_parentheses = True