ci: link create-e2e-accounts ghcr package to the repo via OCI source label

Signed-off-by: Alessandro Yuichi Okimoto <yuichijpn@gmail.com>

Author: cre8ivejp

hack/create-e2e-accounts/Dockerfile

@@ -1,4 +1,4 @@
-FROM golang:1.25 AS builder
+FROM golang:1.26.5 AS builder
 
 WORKDIR /app
 COPY . .
@@ -7,6 +7,10 @@ RUN CGO_ENABLED=0 go build -o create-e2e-accounts .
 
 FROM gcr.io/distroless/base
 
+# Links the ghcr.io package to this repository, so packages created by the
+# image-build workflow automatically grant the repo's GITHUB_TOKEN write access.
+LABEL org.opencontainers.image.source=https://github.com/bucketeer-io/bucketeer
+
 COPY --from=builder /app/create-e2e-accounts /usr/local/bin/
 
 ENTRYPOINT ["create-e2e-accounts"]