build: remove the untracked shadow .goreleaser.yml

A gitignored .goreleaser.yml sat in the repo root, so a bare `goreleaser`
invocation - the default discovery path - picked it up instead of the
.github/goreleaser.yml that CI passes with --config. The two had diverged
completely: the shadow published the GitHub release directly (draft: false),
pushed pgsty/minio:latest from a dockers section, and stamped a different
vendor and artifact naming. Since RPM signing runs on the maintainer's own
machine, that shadow config was one stray `goreleaser release` away from
publishing a mislabelled release and overwriting the Docker latest tag.

Delete the file and drop its .gitignore entry so any future .goreleaser.yml
shows up as untracked and is caught by the release workflow's clean-checkout
check, rather than silently steering local builds. CI is unaffected: it names
its config explicitly. (A copy of the removed file is preserved out of tree
for reference.)

Co-authored-by: Claude <noreply@anthropic.com>

.gitignore

@@ -55,7 +55,6 @@ xattr
 xl-meta
 
 .gitignore
-.goreleaser.yml
 
 dist/