chore(deps): bump the nestjs group across 1 directory with 6 updates

Bumps the nestjs group with 6 updates in the /backend directory:

| Package | From | To |
| --- | --- | --- |
| [@nestjs/common](https://github.com/nestjs/nest/tree/HEAD/packages/common) | `11.1.19` | `11.1.21` |
| [@nestjs/core](https://github.com/nestjs/nest/tree/HEAD/packages/core) | `11.1.19` | `11.1.21` |
| [@nestjs/platform-express](https://github.com/nestjs/nest/tree/HEAD/packages/platform-express) | `11.1.19` | `11.1.21` |
| [@nestjs/swagger](https://github.com/nestjs/swagger) | `11.4.1` | `11.4.3` |
| [nestjs-i18n](https://github.com/ToonvanStrijp/nestjs-i18n) | `10.7.5` | `10.8.4` |
| [@nestjs/testing](https://github.com/nestjs/nest/tree/HEAD/packages/testing) | `11.1.19` | `11.1.21` |



Updates `@nestjs/common` from 11.1.19 to 11.1.21
- [Release notes](https://github.com/nestjs/nest/releases)
- [Commits](https://github.com/nestjs/nest/commits/v11.1.21/packages/common)

Updates `@nestjs/core` from 11.1.19 to 11.1.21
- [Release notes](https://github.com/nestjs/nest/releases)
- [Commits](https://github.com/nestjs/nest/commits/v11.1.21/packages/core)

Updates `@nestjs/platform-express` from 11.1.19 to 11.1.21
- [Release notes](https://github.com/nestjs/nest/releases)
- [Commits](https://github.com/nestjs/nest/commits/v11.1.21/packages/platform-express)

Updates `@nestjs/swagger` from 11.4.1 to 11.4.3
- [Release notes](https://github.com/nestjs/swagger/releases)
- [Commits](nestjs/swagger@11.4.1...11.4.3)

Updates `nestjs-i18n` from 10.7.5 to 10.8.4
- [Release notes](https://github.com/ToonvanStrijp/nestjs-i18n/releases)
- [Commits](toonvanstrijp/nestjs-i18n@v10.7.5...v10.8.4)

Updates `@nestjs/testing` from 11.1.19 to 11.1.21
- [Release notes](https://github.com/nestjs/nest/releases)
- [Commits](https://github.com/nestjs/nest/commits/v11.1.21/packages/testing)

---
updated-dependencies:
- dependency-name: "@nestjs/common"
  dependency-version: 11.1.21
  dependency-type: direct:production
  update-type: version-update:semver-patch
  dependency-group: nestjs
- dependency-name: "@nestjs/core"
  dependency-version: 11.1.21
  dependency-type: direct:production
  update-type: version-update:semver-patch
  dependency-group: nestjs
- dependency-name: "@nestjs/platform-express"
  dependency-version: 11.1.21
  dependency-type: direct:production
  update-type: version-update:semver-patch
  dependency-group: nestjs
- dependency-name: "@nestjs/swagger"
  dependency-version: 11.4.3
  dependency-type: direct:production
  update-type: version-update:semver-patch
  dependency-group: nestjs
- dependency-name: nestjs-i18n
  dependency-version: 10.8.4
  dependency-type: direct:production
  update-type: version-update:semver-minor
  dependency-group: nestjs
- dependency-name: "@nestjs/testing"
  dependency-version: 11.1.21
  dependency-type: direct:development
  update-type: version-update:semver-patch
  dependency-group: nestjs
...

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Author: dependabot[bot]