feat: Rename the disconnect method of each SHSEndpoint to close

The two verbs have the same meaning in this context, and this unifies the two interfaces, which helps type checking in
code using this library.

tests/test_network.py

@@ -145,7 +145,7 @@ async def test_client(mocker: MockerFixture) -> None:
     await client.open()
     reader.append(b"TEST")
     assert (await client.read()) == b"TEST"
-    client.disconnect()
+    client.close()
 
 
 @pytest.mark.asyncio
@@ -155,7 +155,7 @@ async def test_server(mocker: MockerFixture) -> None:
     resolve = Event()
 
     async def _on_connect(_: Any) -> None:
-        server.disconnect()
+        server.close()
         resolve.set()
 
     _, _, _create_mock_server = _server_stream_mocker()