Unbound repodata-patch applies to past and future clang*/llvm* builds

### Comment:

We have a repodata patch without any version/timestamp upper bound at
https://github.com/conda-forge/conda-forge-repodata-patches-feedstock/blob/b0cf9163689b7f63288c45c6b99121aae4cb4ca4/recipe/gen_patch_json.py#L650-L664
that adds some run `constrains` entries to some `clang*`/`llvm*` packages.

Ideally, we'd handle such patches upstream in the feedstocks for newer builds and apply the patch only for already published builds.

xref:
- https://github.com/conda-forge/clangdev-feedstock/issues/281
- https://github.com/conda-forge/conda-forge-repodata-patches-feedstock/pull/686#issuecomment-2016429986