Alan Agius 42e16ddce0 refactor(@angular/ssr): mark @angular/platform-server as optional
Whlist, this package is not really optional, NPM will install the wrong verson of peer dependencies when the Angular CLI is in prerelease mode.

```ts
STDERR:
npm error code ERESOLVE
npm error ERESOLVE unable to resolve dependency tree
npm error
npm error While resolving: test-project@0.0.0
npm error Found: @angular/animations@19.1.0-next.0
npm error node_modules/@angular/animations
npm error   @angular/animations@"^19.1.0-next.0" from the root project
npm error
npm error Could not resolve dependency:
npm error peer @angular/animations@"19.0.1" from @angular/platform-server@19.0.1
npm error node_modules/@angular/platform-server
npm error   peer @angular/platform-server@"^19.1.0-next.0 || ^19.0.0" from @angular/ssr@19.1.0-next.0
npm error   node_modules/@angular/ssr
npm error     @angular/ssr@"19.1.0-next.0" from the root project
npm error
npm error Fix the upstream dependency conflict, or retry
npm error this command with --force or --legacy-peer-deps
```
2024-12-02 13:12:00 +01:00
..