Issues/issue 593 update to zephyr v3 6 0 (#601)

* [WIP] update manifest to zephyr v3.6.0

* [WIP] Deprecated ZTEST_NEW_API adjustments

Zephyr v3.6.0 removed Kconfig ZTEST_NEW_API.
The old ZTEST API is still used by non-Zephyr builds,
so the config setting is moved from `prj.conf` to
the test's CMakeLists.txt as `add_compile_definitions()`.

Verified by:

1. make clean all test

2. ./zephyr/scripts/twister -p unit_testing \
        -T bacnet-stack/zephyr/tests/

---------

Co-authored-by: Gregory Shue <gregory.shue@legrand.com>

test/bacnet/datetime/src/main.c

@@ -602,7 +602,11 @@ static void testDatetimeConvertUTCSpecific(BACNET_DATE_TIME *utc_time,
         local_time->time.hundredths, test_local_time.time.hundredths, NULL);
 }
 
+#ifdef CONFIG_ZTEST_NEW_API
+ZTEST(bacnet_datetime, testDatetimeConvertUTC)
+#else
 static void testDatetimeConvertUTC(void)
+#endif
 {
     BACNET_DATE_TIME local_time;
     BACNET_DATE_TIME utc_time;