fix(@angular/ssr): designate package as side-effect free

Add `sideEffects` in the `package.json`

Author: alan-agius4

packages/angular/ssr/package.json

@@ -30,6 +30,7 @@
     "@angular/router": "19.0.0-next.10",
     "@bazel/runfiles": "^5.8.1"
   },
+  "sideEffects": false,
   "schematics": "./schematics/collection.json",
   "repository": {
     "type": "git",