There's a closed pull request on the void-packages repository

xbps: Remove reduntant patch
https://github.com/void-linux/void-packages/pull/29424

Description:
This patch no longer does anything as $(CFLAGS) is now included in the libxbps.so rule in the Makefile in lib/Makefile as seen [here](https://github.com/void-linux/xbps/blob/master/lib/Makefile).