tests: Use __tracebackhide__ in wait_for methods.

tests/integration/quteprocess.py

@@ -224,6 +224,7 @@ class QuteProc(testprocess.Process):
         self._data is cleared after every test to provide at least some
         isolation.
         """
+        __tracebackhide__ = True
         return super().wait_for(timeout, **kwargs)
 
     def wait_for_load_finished(self, path, timeout=15000):

tests/integration/testprocess.py

@@ -227,6 +227,7 @@ class Process(QObject):
         Return:
             The matched line.
         """
+        __tracebackhide__ = True
         if timeout is None:
             if 'CI' in os.environ:
                 timeout = 15000