[Bug]: `container builder delete` should support `rm` alias.

[jglogan]

I have done the following

• I have searched the existing issues
• If possible, I've reproduced the issue using the 'main' branch of this project

Steps to reproduce

Prompted by #385. All other instances of the delete subcommand also accept rm.

Current behavior

% container rm foo
foo
% container image rm foo
foo:latest
Reclaimed 78.6 MB in disk space
% container builder rm
Error: Unexpected argument 'rm'
Usage: container builder <subcommand>
  See 'container builder --help' for more information.
%

Expected behavior

container builder rm functions equivalently to container builder delete.

% container builder rm
%

Environment

- OS: Tahoe beta
- Xcode: Xcode 26 beta
- Container: main

Relevant log output

Code of Conduct

• I agree to follow this project's Code of Conduct

[jglogan]

Closed by #505.