Donate provider-upjet-harbor to crossplane-contrib

Hi!
I've created and maintained (regular releases, CVE remediations) [provider-upjet-harbor](https://github.com/jonasz-lasut/provider-upjet-harbor), which is a provider that allows users to manage configuration of Harbor instances. Harbor is a CNCF graduated OCI registry - https://goharbor.io/

Details as per governance note:

Name: provider-upjet-harbor

Purpose: Configure every aspect of a Harbor instance from IAM to repository configuration using Crossplane managed resources. Examples of usage: https://github.com/jonasz-lasut/provider-upjet-harbor/tree/main/examples

Maintainer team: Just me right now, open to adding more maintainers if the community adopts this provider.

Long term commitment: I'm involved with Crossplane ecosystem and I'm a maintainer of multiple different providers for a long period of time and I plan to continue my work on the ecosystem

Review the governance note and the linked provider-upjet-harbor repository, including its examples, to understand the proposed donation. Confirm the organization’s requirements for accepting and maintaining the provider, and consider the work complete when the governance decision and any required ownership or maintainer changes are recorded.

Written by the indexing model from the issue text.