Refactor download_state.py and test_download_state.py

- Remove the `get_session_ratio` method from `DownloadState` class in download_state.py
- Remove the assertion for `get_session_ratio()` in test_download_state.py

src/tribler/core/components/libtorrent/download_manager/download_state.py

@@ -153,13 +153,6 @@ def total_payload_download(self) -> int:
             return 0
         return self.lt_status.total_payload_download
 
-    def get_session_ratio(self) -> float:
-        """ Returns the seeding ratio of the download for the current session.
-        """
-        if not self.lt_status or not self.total_payload_download:
-            return 0
-        return self.total_payload_upload / self.total_payload_download
-
     def get_all_time_ratio(self) -> float:
         """ Returns the accumulated seeding ratio of the download across multiple sessions.
         """

src/tribler/core/components/libtorrent/tests/test_download_state.py

@@ -58,7 +58,6 @@ def test_getters_setters_2(mock_download, mock_lt_status):
 
     assert download_state.total_payload_upload == 30
     assert download_state.total_payload_download == 100
-    assert download_state.get_session_ratio() == 0.3
 
     assert download_state.all_time_upload == 200
     assert download_state.all_time_download == 1000