Bump node from 16 to 21 (#433)

Bumps node from 16 to 21.

---
updated-dependencies:
- dependency-name: node
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Dockerfile

@@ -1,5 +1,5 @@
 # node layer to build static assets
-FROM node:16 AS nodejs
+FROM node:21 AS nodejs
 WORKDIR /usr/src/app/
 COPY package.json yarn.lock ./
 RUN yarn install