Tag releases on submodules to enable version imports

[ctlong]

Is your feature request related to a problem? Please describe.
Yes, when I'm attempting to import github.com/vmware/govmomi/govc and github.com/vmware/govmomi/vcsim in another (private) module, it can only pull the digests tags (e.g. v0.0.0-20250318122354-63177e025193).

Describe the solution you'd like
New versions seem like it's intended to be for all modules in this repo, not just for govmomi, right? In that case, tags should be added for the submodules as well (e.g. govc/v0.49.0) so that Go knows that there's a new release of those submodules.

Describe alternatives you've considered
Splitting out the submodules into separate repos? Doesn't seem necessary though.

Additional context
Other repo examples:

• https://github.com/open-telemetry/opentelemetry-collector-contrib/tags
• https://github.com/hashicorp/vault/tags

[github-actions]

Howdy 🖐   ctlong ! Thank you for your interest in this project. We value your feedback and will respond soon.

If you want to contribute to this project, please make yourself familiar with the CONTRIBUTION guidelines.

[tenthirtyam]

Will discuss with @dougm and @akutz.