Update Node.js to v21.6

Dockerfile

-FROM --platform=$BUILDPLATFORM public.ecr.aws/docker/library/node:21.5-alpine@sha256:9b54d010b382f0ef176dc93cd829bd4f2a905092b260746b3999aa824c9b7121 AS buildJS
+FROM --platform=$BUILDPLATFORM public.ecr.aws/docker/library/node:21.6-alpine@sha256:e8894d38c2f0eed0131e781e8f834578afc28d69441213ece74b229aef9385b0 AS buildJS
 WORKDIR /app
 COPY . ./
 RUN yarn install --frozen-lockfile && \