Bump json-schema from 0.2.3 to 0.4.0 in /tests/performance

Bumps [json-schema](https://github.com/kriszyp/json-schema) from 0.2.3 to 0.4.0.
- [Release notes](https://github.com/kriszyp/json-schema/releases)
- [Commits](https://github.com/kriszyp/json-schema/compare/v0.2.3...v0.4.0

)

---
updated-dependencies:
- dependency-name: json-schema
  dependency-type: indirect
...

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

For https://github.com/turt2live/matrix-media-repo/issues/365

Add users' usage statistics (admin) API endpoint

Allow for queries to early-exit if the requests have been aborted.

endpoint to be accessible to homeserver admins.

There was no need to lock it down to only global admins.

module.

Prepare for function to be used by multiple modules.