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When using the application build system via the `@angular/build` package(default for new projects starting in v20), a new experimental unit-testbuilder is available that initially uses vitest. This experimental systemis intended to provide support for investigation of future unit testingefforts within the Angular CLI. As this is experimental, no SemVer guaranteesare provided, the API and behavior may change, and there may be unexpectedbehavior. Available test runners may be added or removed as well.The setup is somewhat different than the previous unit-testing builders.It uses a similar mechanism to that of the `dev-server` and requires a`buildTarget` option. This allows the code building aspects of the unit-testing process to leverage pre-existing option values that are alreadydefined for development. If differing option values are required for testing,an additional build target configuration specifically for testing can beused.The current vitest support has multiple caveats including but not limited to:* No watch support* `jsdom` based testing only (`jsdom` must be installed in the project)* Custom vitest configuration is not supportedAn example configuration that would replace the `test` target for a projectis as follows:```"test": {    "builder": "@angular/build:unit-test",    "options": {        "tsConfig": "tsconfig.spec.json",        "buildTarget": "::development",        "runner": "vitest"    }}```