Bump node from 16.9.0-alpine to 17.1.0-alpine in /file-server (#1202)

Bumps node from 16.9.0-alpine to 17.1.0-alpine.

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

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

file-server/Dockerfile

@@ -4,7 +4,7 @@ FROM compdem/polis-client-admin:${TAG}          as admin
 FROM compdem/polis-client-participation:${TAG}  as participation
 FROM compdem/polis-client-report:${TAG}         as report
 
-FROM node:16.9.0-alpine
+FROM node:17.1.0-alpine
 
 WORKDIR /app