Bump flat and @serverless/enterprise-plugin

Bumps [flat](https://github.com/hughsk/flat) and [@serverless/enterprise-plugin](https://github.com/serverless/enterprise-plugin). These dependencies needed to be updated together.

Updates `flat` from 4.1.0 to 5.0.2
- [Commits](hughsk/flat@4.1.0...5.0.2)

Updates `@serverless/enterprise-plugin` from 3.2.0 to 3.8.4
- [Release notes](https://github.com/serverless/enterprise-plugin/releases)
- [Changelog](https://github.com/serverless/dashboard-plugin/blob/main/CHANGELOG.md)
- [Commits](https://github.com/serverless/enterprise-plugin/compare/v3.2.0...v3.8.4)

---
updated-dependencies:
- dependency-name: flat
  dependency-type: indirect
- dependency-name: "@serverless/enterprise-plugin"
  dependency-type: indirect
...

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Author: dependabot[bot]