Rename workspace name to `rules_swift`

[UebelAndre]

The guidance on https://bazel.build/rules/deploying#workspace suggests the workspace name should be renamed to rules_swift.

If your rules belong to the bazelbuild organization, you must use rules_ (such as rules_mockascript).

I think that would be a great change but wondering what the maintainers think.

[keith]

i think the general hope here is that folks drop the repo_name from bzlmod at some point, but right now i don't think we want to break workspace users, and it's probably too soon to assume most folks are using bzlmod. The release notes could be changed but I went with including the repo_name for the copy-pasta as folks migrated