test: improve coverage and raise threshold to 80% (#154)

tests/test_plugins.py

@@ -1,9 +1,18 @@
+from collections.abc import Iterator
+
 import pytest
 
 from takopi import plugins
 from tests.plugin_fixtures import FakeEntryPoint, install_entrypoints
 
 
+@pytest.fixture(autouse=True)
+def _reset_plugin_state() -> Iterator[None]:
+    plugins.reset_plugin_state()
+    yield
+    plugins.reset_plugin_state()
+
+
 def test_list_ids_does_not_load_entrypoints(monkeypatch) -> None:
     calls = {"count": 0}