Bump goreleaser/goreleaser-pro in /.buildkite (#321)

Bumps goreleaser/goreleaser-pro from v2.0.1-pro to v2.1.0-pro.

---
updated-dependencies:
- dependency-name: goreleaser/goreleaser-pro
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

.buildkite/Dockerfile

@@ -1,4 +1,4 @@
 # This uses the upstream image without any changes intentionally.
 # This allows dependabot to keep this version up-to-date for us automatically, since it does not work with
 # docker-compose directly
-FROM goreleaser/goreleaser-pro:v2.0.1-pro@sha256:aefa05cc637661b1b871aa68945736f71cfba84b5277476045d7beee33a415e6
+FROM goreleaser/goreleaser-pro:v2.1.0-pro@sha256:cdd28fbaac9bd631e5ed7ffaf38df074702b2c655b97cdc54a939ce24c99ef0f