Cargo should warn when workspace "exclude" does not match anything #17089

Problem

I just found that a workspace configuration with

[workspace]
members = ["crates/*"]
exclude = ["crates/excluded"]

Does not warn when excluded does not exist.

Proposed Solution

Cargo should warn when a member of the workspace.exclude array does not match anything.

Notes

Had a look at open issues and this seems partially related to #4377 but I did not find any other open issue that explicitly notes what I wrote above. Maybe I missed it of course 😆