chore(deps): bump node in /sharedb.planx.uk

Bumps node from 18.16.1-alpine to 18.19.1-alpine.

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

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

sharedb.planx.uk/Dockerfile

@@ -1,5 +1,5 @@
 # 18.16.1 = LTS
-FROM node:18.16.1-alpine as base
+FROM node:18.19.1-alpine as base
 
 WORKDIR /sharedb
 RUN npm install -g [email protected]