Don't use StringEnum subclasses over Qt Signal definition (#104)

* Don't use 'StringEnum' subclasses over Qt Signal definition

* Testing

* Testing

* Testing

napari_plugin_manager/_tests/test_qt_plugin_dialog.py

@@ -14,9 +14,7 @@
 from qtpy.QtCore import QMimeData, QPointF, Qt, QUrl
 from qtpy.QtGui import QDropEvent
 
-if (qtpy.API_NAME == 'PySide2') or (
-    sys.version_info[:2] > (3, 10) and platform.system() == "Linux"
-):
+if qtpy.API_NAME == 'PySide2' and sys.version_info[:2] > (3, 10):
     pytest.skip(
         "Known PySide2 x Python incompatibility: "
         "... object cannot be interpreted as an integer",

napari_plugin_manager/qt_plugin_dialog.py

@@ -17,6 +17,7 @@
 from napari.plugins.utils import normalized_name
 from napari.settings import get_settings
 from napari.utils.misc import (
+    StringEnum,
     parse_version,
     running_as_constructor_app,
 )
@@ -104,9 +105,7 @@ class PluginListItem(QFrame):
     author, source, version, and buttons to update, install/uninstall, etc."""
 
     # item, package_name, action_name, version, installer_choice
-    actionRequested = Signal(
-        QListWidgetItem, str, InstallerActions, str, InstallerTools
-    )
+    actionRequested = Signal(QListWidgetItem, str, StringEnum, str, StringEnum)
 
     def __init__(
         self,