build(deps): bump @aws-sdk/client-s3 in /apps/OpenSignServer

Bumps [@aws-sdk/client-s3](https://github.com/aws/aws-sdk-js-v3/tree/HEAD/clients/client-s3) from 3.879.0 to 3.888.0.
- [Release notes](https://github.com/aws/aws-sdk-js-v3/releases)
- [Changelog](https://github.com/aws/aws-sdk-js-v3/blob/main/clients/client-s3/CHANGELOG.md)
- [Commits](https://github.com/aws/aws-sdk-js-v3/commits/v3.888.0/clients/client-s3)

---
updated-dependencies:
- dependency-name: "@aws-sdk/client-s3"
  dependency-version: 3.888.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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Author: dependabot[bot]