Fix failure in test_utf8_uploads on CircleCI

- on CircleCI, otherwise it fails with

STDERR:   File "/home/circleci/project/./tests/test_utf8_uploads.py", line 23, in <module>
STDERR:     from tcms.settings.common import FILE_UPLOAD_MAX_SIZE
STDERR: ModuleNotFoundError: No module named 'tcms'

and it looks like setting PYTHONPATH externally doesn't work. Instead
make sure the test script configures sys.path internally so it can find
all of the imports

tests/test_http.sh

@@ -69,7 +69,7 @@ username = testadmin
 password = password
 _EOF_
 
-        rlRun -t -c "PYTHONPATH=../Kiwi ./tests/test_utf8_uploads.py -v"
+        rlRun -t -c "./tests/test_utf8_uploads.py -v"
     rlPhaseEnd
 
     rlPhaseStartTest "Should send ETag header"

tests/test_utf8_uploads.py

@@ -1,12 +1,14 @@
 #!/usr/bin/env python3
 
 #
-# Copyright (c) 2022-2023 Kiwi TCMS project. All rights reserved.
+# Copyright (c) 2022-2024 Kiwi TCMS project. All rights reserved.
 # Author: Alexander Todorov <info@kiwitcms.org>
 #
 
 import base64
+import os
 import ssl
+import sys
 import tempfile
 import unittest
 from unittest.mock import patch
@@ -15,6 +17,9 @@
 import requests
 from tcms_api import TCMS
 
+tcms_root_path = os.path.abspath(os.path.join(os.path.dirname(__file__), ".."))
+sys.path.append(tcms_root_path)
+
 from tcms.settings.common import FILE_UPLOAD_MAX_SIZE
 
 try: