chore(deps): upgrade json-schema version to 0.4.0

[jsjoeio]

This PR fixes the version of json-schema used in our /test directory to resolve a security vulnerability.

Fixes N/A

[github-actions]

✨ Coder.com for PR #4543 deployed! It will be updated on every commit.

• Host: https://codercom-c4jykqr5t-codercom.vercel.app/docs/code-server
• Last deploy status: success
• Commit: 47a98cb
• Workflow status: https://github.com/cdr/code-server/actions/runs/1491726396

[codecov]

Codecov Report

Merging #4543 (81f65b1) into main (bd09533) will not change coverage.
The diff coverage is n/a.

❗ Current head 81f65b1 differs from pull request most recent head 47a98cb. Consider uploading reports for the commit 47a98cb to get more accurate results

@@           Coverage Diff           @@
##             main    #4543   +/-   ##
=======================================
  Coverage   65.38%   65.38%           
=======================================
  Files          30       30           
  Lines        1664     1664           
  Branches      335      335           
=======================================
  Hits         1088     1088           
  Misses        488      488           
  Partials       88       88           

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