fix: remove discussion_category_name from goreleaser config

Discussions are not enabled on this repo; GoReleaser was failing trying
to post a release announcement to a non-existent Discussions category.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: lucasmodrich

.goreleaser.yaml

@@ -50,4 +50,3 @@ changelog:
       - '^docs:'
 release:
   prerelease: auto
-  discussion_category_name: Release