ttfw: fix incorrect relative import for python3

tools/ci/python_packages/tiny_test_fw/DUT.py

@@ -53,7 +53,7 @@ except ImportError:
 import serial
 from serial.tools import list_ports
 
-import Utility
+from . import Utility
 
 
 class ExpectTimeout(ValueError):

tools/ci/python_packages/tiny_test_fw/Env.py

@@ -19,7 +19,7 @@ import functools
 
 import netifaces
 
-import EnvConfig
+from . import EnvConfig
 
 
 def _synced(func):

tools/ci/python_packages/tiny_test_fw/TinyFW.py

@@ -22,10 +22,10 @@ from datetime import datetime
 
 import junit_xml
 
-import Env
-import DUT
-import App
-import Utility
+from . import Env
+from . import DUT
+from . import App
+from . import Utility
 
 
 class DefaultEnvConfig(object):

tools/ci/python_packages/ttfw_idf/__init__.py

@@ -15,8 +15,8 @@ import os
 import re
 
 from tiny_test_fw import TinyFW, Utility
-from IDFApp import IDFApp, Example, LoadableElfExample, UT  # noqa: export all Apps for users
-from IDFDUT import IDFDUT, ESP32DUT, ESP32S2DUT, ESP8266DUT, ESP32QEMUDUT  # noqa: export DUTs for users
+from .IDFApp import IDFApp, Example, LoadableElfExample, UT  # noqa: export all Apps for users
+from .IDFDUT import IDFDUT, ESP32DUT, ESP32S2DUT, ESP8266DUT, ESP32QEMUDUT  # noqa: export DUTs for users
 
 
 def format_case_id(chip, case_name):