Bump terser and @angular-devkit/build-angular

Bumps [terser](https://github.com/terser/terser) to 5.15.1 and updates ancestor dependency [@angular-devkit/build-angular](https://github.com/angular/angular-cli). These dependencies need to be updated together.


Updates `terser` from 4.7.0 to 5.15.1
- [Release notes](https://github.com/terser/terser/releases)
- [Changelog](https://github.com/terser/terser/blob/master/CHANGELOG.md)
- [Commits](terser/terser@v4.7.0...v5.15.1)

Updates `@angular-devkit/build-angular` from 0.1000.5 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](https://github.com/angular/angular-cli/commits/15.0.2)

---
updated-dependencies:
- dependency-name: terser
  dependency-type: indirect
- dependency-name: "@angular-devkit/build-angular"
  dependency-type: direct:development
...

Signed-off-by: dependabot[bot] <[email protected]>