test_preceding_whitespace fails on Python 3.13

[dotlambda]

... because

The compiler now strips common leading whitespace from every line in a docstring.

See https://docs.python.org/3/whatsnew/3.13.html#other-language-changes.

[JayBazuzi]

python/cpython#81283 (comment).

Chance of breaking things with this change? not impossible, but extremely minor. Something using docstrings as data and depending on leading indentation whitespace preservation would not like this. I am not aware of anything that would ever do that.

Ouch.

[JayBazuzi]

Temporarily disabled this test under Python 3.13 to unblock CI. See be07544.

[nitsanavni]

IMHO this docstring limitation is acceptable for inline approvals.
If the user needs to verify whitespace in fine detail, we should recommend non-inline approvas for that.