gnucash stable: Replace deprecated gdk_pixbuf_new_from_xpm_data

[John Ralls]

Updated	 via  https://github.com/Gnucash/gnucash/commit/5b0d70b7 (commit)
	from  https://github.com/Gnucash/gnucash/commit/ac4a6808 (commit)



commit 5b0d70b7aa4f9439c60881784b5e1c391d8de9f1
Author: John Ralls <jralls at ceridwen.us>
Date:   Tue Sep 23 14:10:47 2025 -0700

    Replace deprecated gdk_pixbuf_new_from_xpm_data



Summary of changes:
 gnucash/import-export/import-backend.cpp           | 23 +++++++++++++++++++---
 .../import-export/test/gtest-import-backend.cpp    | 10 ++++++++++
 2 files changed, 30 insertions(+), 3 deletions(-)