xcb-util-errors: fix racing on out of source tree build
While building out of source tree, there is a racing issue
on the existence of dir ./src
...
python3 ../sources/xcb-util-errors-1.0.1/src/extensions.py src/extensions.c.tmp path-to/1.0.1/recipe-sysroot/usr/share/xcb/*.xml && \
mv src/extensions.c.tmp src/extensions.c
File "src/extensions.py", line 91, in <module>
output = open(output_file, "w")
FileNotFoundError: [Errno 2] No such file or directory: 'src/extensions.c.tmp'
make: *** [Makefile:1435: src/extensions.c] Error 1
...
Explicitly create dir ./src before generating src/extensions.c.tmp
Inherit python3native to instead of host python3 to run python script