CI: fix zephyr build for v3.7 and later

The current CI uses the latest from main for zephyr build tests.
This has been broken sometime after v3.6 and before v3.7
In Zephyr v3.7 and later, use of GNU style constructors requires a kconfig
value to be defined.  This same kconfig value will cause an error in v3.6
or earlier.

The test framework intentionally uses GNU constructors for the base level
of its framework and version.c uses this to register its test.

The test/system/zephyr/ level override the default META_ADD_TEST() macro
and creates unique functions that main.c then calls explicitly in function
metal_test_add_functions().

This right now the only constructor used if for version.c but it still
intentionally used.

Since we use the latest for CI, define the value so CI will complete.

Signed-off-by: Bill Mills <bill.mills@linaro.org>

.github/actions/build_ci/entrypoint.sh

@@ -91,8 +91,11 @@ build_zephyr(){
 	cd ./zephyr &&
 	source zephyr-env.sh &&
 	cd ../.. &&
-	# The prj.conf is mandatory for cmake execution, create a void file.
-	touch prj.conf &&
+	# The prj.conf is mandatory for cmake execution, create a file.
+	# The base level of the test infrastucture intentially uses constructors so
+	#   we must define this config item in v3.7.0 or later
+	#   HOWEVER, this define will cause cmake to fail for v3.6 or earlier
+	echo "CONFIG_STATIC_INIT_GNU=y" >touch prj.conf &&
 	# Add dummy fields in the VERSION file to fix compatibility with Zephyr
 	# version.cmake file
  	echo "PATCHLEVEL = 0" >>VERSION &&