fix pep484 issue for most recent mypy

Change-Id: I1d5f657121914b091c5c3c70e24841d2036256a2

diff --git a/alembic/runtime/plugins.py b/alembic/runtime/plugins.py
index be1d590f55f5584e6bfc72e00c3d9cebdcd0db72..cbcc8ee86278b9aaebd0c2c42b4fc323cb536694 100644 (file)
--- a/alembic/runtime/plugins.py
+++ b/alembic/runtime/plugins.py
@@ -15,7 +15,7 @@ from ..util import PriorityDispatcher
 if TYPE_CHECKING:
     from ..util import PriorityDispatchResult
 
-_all_plugins = {}
+_all_plugins: dict[str, Plugin] = {}
 
 
 log = logging.getLogger(__name__)