The change in commit 86ad7cc886 (project: Only define non-cache vars if
already defined, 2024-09-15, v3.30.4~2^2) was meant to only check for
non-cache variables when deciding whether to set non-cache project
variables for the current call. However, it erroneously checked for any
variable, including cache variables. This gives the intended result on
the first run, but on subsequent runs a cache variable will exist that
did not on the first run, leading to different behavior between the two
runs. Fix the logic to only check for a pre-existing non-cache
variable, as was originally intended.
Fixes: #26355
Add a 3.30.3 release note for commit c1ece78d11 (project: non cache
<project> prefix variables are also created, 2024-08-27, v3.30.3~2^2).
Prepare a 3.30.4 release note for commit 86ad7cc886 (project: Only
define non-cache vars if already defined, 2024-09-15).
Define the `Python_DEFINITIONS` variable for the support of free
threaded Python developments on Windows.
This is a complement to commit 9a0dee7257 (FindPython: Add support for
free threaded python, 2024-05-30).
Add section headers similar to the 3.29 release notes and move each
individual bullet into an appropriate section. Revise a few bullets.
Drop the `CXX_MODULE_STD` release note since it is an experimental
feature.
