[release-0.18] Update hack/release.sh (#1142)

* [release-0.18] Update hack/release.sh

 no arm build for this backport release

* Update date in CHANGELOG

Author: navidshaikh

CHANGELOG.adoc

@@ -12,7 +12,7 @@
 | https://github.com/knative/client/pull/[#]
 ////
 
-## v0.18.4 (2020-11-25)
+## v0.18.4 (2020-11-26)
 
 [cols="1,10,3", options="header", width="100%"]
 |===

hack/release.sh

@@ -39,7 +39,7 @@ function build_release() {
   GOOS=linux GOARCH=s390x go build -mod=vendor -ldflags "${ld_flags}" -o ./kn-linux-s390x ./cmd/...
   echo "🚧 🐳 Building the container image"
   ko resolve --strict ${KO_FLAGS} -f config/ > kn-image-location.yaml
-  ARTIFACTS_TO_PUBLISH="kn-darwin-amd64 kn-linux-amd64 kn-linux-arm64 kn-windows-amd64.exe kn-linux-s390x kn-image-location.yaml"
+  ARTIFACTS_TO_PUBLISH="kn-darwin-amd64 kn-linux-amd64 kn-windows-amd64.exe kn-linux-s390x kn-image-location.yaml"
   sha256sum ${ARTIFACTS_TO_PUBLISH} > checksums.txt
   ARTIFACTS_TO_PUBLISH="${ARTIFACTS_TO_PUBLISH} checksums.txt"
   echo "🧮     Checksum:"