chore: add flatpak tests

tests/test_process_detection.py

@@ -1,3 +1,4 @@
+import pytest
 import unittest
 from unittest.mock import patch
 
@@ -9,6 +10,8 @@ from dzgui.const.constants import (
 )
 from dzgui.init import proc
 
+pytestmark = pytest.mark.flatpak
+
 
 class TestSteamDetection(unittest.TestCase):
     def test_flatpak_detection_with_multiple_running_apps(self):