fix(oci collector): support registry endpoints with ports

[brandtkeller]

Description of the PR

This change is a minor modification to the minimum registry validation that performs a dns lookup. To my knowledge and testing - it did not previously support registries that had ports included from the guaccollect registry command.

My motivation is to enable a number of registry deployment scenarios that may be running on specific ports - particularly in the deployment to a Kubernetes cluster whereby the oci collector can target internal service endpoints.

Fixes #2826

PR Checklist

• All commits have a Developer Certificate of Origin (DCO) -- they are generated using -s flag to git commit.
• All new changes are covered by tests
• If GraphQL schema is changed, make generate has been run
• If GraphQL schema is changed, GraphQL client updates/additions have been made
• If OpenAPI spec is changed, make generate has been run
• If ent schema is changed, make generate has been run
• If collectsub protobuf has been changed, make proto has been run
• All CI checks are passing (tests and formatting)
• All dependent PRs have already been merged

[brandtkeller]

Adding this - looks to be an inconsistency between guacone and guaccollect - but I believe this is the correct data source for the registry command.