Bump eventsource and @angular/cli

Removes [eventsource](https://github.com/EventSource/eventsource). It's no longer used after updating ancestor dependency [@angular/cli](https://github.com/angular/angular-cli). These dependencies need to be updated together.


Removes `eventsource`

Updates `@angular/cli` from 1.7.4 to 15.0.2
- [Release notes](https://github.com/angular/angular-cli/releases)
- [Changelog](https://github.com/angular/angular-cli/blob/main/CHANGELOG.md)
- [Commits](angular/angular-cli@v1.7.4...15.0.2)

---
updated-dependencies:
- dependency-name: eventsource
  dependency-type: indirect
- dependency-name: "@angular/cli"
  dependency-type: direct:development
...

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Author: dependabot[bot]