gnucash stable: Update minumum Python version to 3.8.

[John Ralls]

Updated	 via  https://github.com/Gnucash/gnucash/commit/7eaa177e (commit)
	from  https://github.com/Gnucash/gnucash/commit/8ebac5b5 (commit)



commit 7eaa177eae24fc87e32a09a038c61457840380ca
Author: John Ralls <jralls at ceridwen.us>
Date:   Thu Feb 29 16:12:53 2024 -0800

    Update minumum Python version to 3.8.
    
    Required to support Python 3.13 and later because the new C API used
    in 1d8c525af was introduced in Python 3.8; the previous API was a
    holdover from Python 2, deprecated in 3.7, and is removed in 3.13.



Summary of changes:
 CMakeLists.txt      | 2 +-
 README.dependencies | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)