Disable buildx provenance to fix ECR manifest list error (#101)

Docker buildx enables provenance attestations by default, which causes
each platform image to be pushed as a manifest list rather than a plain
image manifest. ECR Public rejects creating a multi-arch manifest that
references another manifest list, resulting in a release failure.

Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: wesleyjellis

src/.goreleaser.yml

@@ -36,6 +36,7 @@ dockers:
     - "--label=org.opencontainers.image.version={{ .Tag }}"
     - "--build-arg=VERSION={{ .Tag }}"
     - "--platform=linux/amd64"
+    - "--provenance=false"
     goos: linux
     goarch: amd64
   -
@@ -49,6 +50,7 @@ dockers:
     - "--label=org.opencontainers.image.version={{ .Tag }}"
     - "--build-arg=VERSION={{ .Tag }}"
     - "--platform=linux/arm64"
+    - "--provenance=false"
     goos: linux
     goarch: arm64
 docker_manifests: