(promote) release: build v6.4.1203#281

jdpleiness wants to merge 1 commit intointernal/release-v6.4.1203sourcegraph/deploy-sourcegraph-k8s:internal/release-v6.4.1203from

promote/release-v6.4.1203sourcegraph/deploy-sourcegraph-k8s:promote/release-v6.4.1203Copy head branch name to clipboard