fix(ci): fix warnings by registering the pytest marker

- ```
/workspace/python-sensor/tests/agent/test_host.py:125: PytestUnknownMarkWarning: Unknown pytest.mark.original - is this a typo?  You can register custom marks to avoid this warning - for details, see https://docs.pytest.org/en/stable/how-to/mark.html
    @pytest.mark.original
```

Signed-off-by: Varsha GS <varsha.gs@ibm.com>

Author: GSVarsha

pytest.ini

@@ -7,3 +7,5 @@ pythonpath = src
 testpaths = 
     tests
     tests_aws
+markers =
+    original: mark test to use the original method instead of the mocked ones under `conftest.py`