Delete.namespace does not accept numbered args

[rlmark]

It looks like delete.namespace does not accept a numbered arg. Its behavior when provided a text-based name is unaffected (works great!)

Transcript reproduction:

ns-test/main> builtins.mergeio

oneNamespace.termThing =
  List.map Nat.increment [1,2,3]

ns-test/main> update
ns-test/main> ls

ns-test/main> delete.namespace 2

Environment (please complete the following information):

• unison version: release/0.5.50 (built on 2025-11-10)
• OS/Architecture: macOS Tahoe 26.1, Apple-silicon