feat: add public diracx.tasks.depends module

Re-export NoTransaction from the plumbing layer so task authors
can import from diracx.tasks.depends rather than reaching into
plumbing internals.

Author: chrisburr

diracx-tasks/src/diracx/tasks/depends.py

@@ -0,0 +1,7 @@
+"""Public dependency injection markers for task authors."""
+
+from __future__ import annotations
+
+from diracx.tasks.plumbing.depends import NoTransaction
+
+__all__ = ("NoTransaction",)