Recently, LOCI changed its default so images are python3 if nothing is
specified at the *docker_image files. With the recent upversion of LOCI
in the build tools [1], we need to explictly set PYTHON3=no to images
that are still using python2. This commit fixes the StarlingX images to
use this parameter
TEST PLAN
PASS build the stx-fm-rest-api image on the stable branch
[1] 00bd632a68
Closes-Bug: #1958696
Signed-off-by: Thiago Brito <thiago.brito@windriver.com>
Change-Id: Icc80f5ca3f2031537e45ab8ff35420250522cb34
e0fba90bdf