Bump node from 20.5-bookworm-slim to 21.7-bookworm-slim

Bumps node from 20.5-bookworm-slim to 21.7-bookworm-slim.

---
updated-dependencies:
- dependency-name: node
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>

Dockerfile

@@ -1,7 +1,7 @@
 # -----------------------------------------------
 # Stage: npm dependencies
 # -----------------------------------------------
-FROM node:20.5-bookworm-slim AS npm-builder
+FROM node:21.7-bookworm-slim AS npm-builder
 
 # Install Debian dependencies
 RUN apt-get update -y && \