Bump node from 25.8.2 to 25.9.0 in /docker in the docker group

Bumps the docker group in /docker with 1 update: node.


Updates `node` from 25.8.2 to 25.9.0

---
updated-dependencies:
- dependency-name: node
  dependency-version: 25.9.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
  dependency-group: docker
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

docker/Dockerfile

@@ -2,7 +2,7 @@
 # Use amd64 for building .js and .css (which are platform agnostic),
 # and then copy to platform-specific nginx image
 
-FROM --platform=linux/amd64 node:25.8.2 AS build
+FROM --platform=linux/amd64 node:25.9.0 AS build
 
 WORKDIR /app