Feature request: add a delete endpoint to remove specific plugin versions from the marketplace

Use case - we'd like to auto-purge old plugin versions in the marketplace. I didn't see an endpoint for deleting plugin versions. This issue is a feature request for this.

No files or tests are named. Start by reviewing the existing marketplace client endpoint definitions and their tests, then identify how plugin versions are addressed and how similar mutating requests are represented. Done should include a defined deletion operation for a specific plugin version with corresponding coverage.

Written by the indexing model from the issue text.