Archive this repo

### Comment:

References:
- https://github.com/conda-forge/admin-requests/pull/1917
- https://github.com/conda-forge/linkml-feedstock/pull/7

The upstream [linkml-runtime repo](https://github.com/linkml/linkml-runtime) was merged into [linkml](https://github.com/linkml/linkml/tree/main/packages/linkml_runtime#readme).

`linkml-runtime` is no longer testable in isolation (it imports `linkml`), and both are missing something needing the main GitHub tarball, so there isn't much reason to keep the two separate.

Once the above pull requests go through, this repository should be archived.

Review admin-requests#1917 and linkml-feedstock#7 first, then confirm that linkml-runtime has been merged into linkml. Once those prerequisites are complete, archive conda-forge/linkml-runtime-feedstock and verify that the repository is archived.

Written by the indexing model from the issue text.