fix: catch update notification exceptions (#1278)

* feat: add test for failing GitHub API call.

* fix: don't raise exceptions in get_most_recent_release_version.

* style: apply ruff.

* That not should not have been there.

tests/qt/test_about_modal.py

@@ -0,0 +1,14 @@
+from pytestqt.qtbot import QtBot
+
+from tagstudio.qt.mixed.about_modal import AboutModal
+
+
+def test_github_api_unavailable(qtbot: QtBot, mocker) -> None:
+    mocker.patch(
+        "requests.get",
+        side_effect=ConnectionError(
+            "Failed to resolve 'api.github.com' ([Errno -3] Temporary failure in name resolution)"
+        ),
+    )
+    modal = AboutModal("/tmp")
+    qtbot.addWidget(modal)