gnucash stable: Fix Typo in previous commit, use Python3_INCLUDE_DIRS

[Robert Fewell]

Updated	 via  https://github.com/Gnucash/gnucash/commit/891e3936 (commit)
	from  https://github.com/Gnucash/gnucash/commit/29b7a909 (commit)



commit 891e39363d2d793ca676b8f8f3cf4086d1f5e419
Author: Robert Fewell <14uBobIT at gmail.com>
Date:   Fri Aug 18 10:51:12 2023 +0100

    Fix Typo in previous commit, use Python3_INCLUDE_DIRS



Summary of changes:
 gnucash/python/CMakeLists.txt | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)