chore: add scripts for installing new fixture dependencies

Author: pieh

package.json

@@ -26,6 +26,9 @@
     "pretest:fixtures:browser-builder": "cd tests/fixtures/browser-builder && npm ci",
     "pretest:fixtures:prerender-false": "cd tests/fixtures/prerender-false && npm ci",
     "pretest:fixtures:angular-17": "cd tests/fixtures/angular-17 && npm ci",
+    "pretest:fixtures:angular-19-common-engine": "cd tests/fixtures/angular-19-common-engine && npm ci",
+    "pretest:fixtures:angular-19-app-engine": "cd tests/fixtures/angular-19-app-engine && npm ci",
+    "pretest:fixtures:angular-19-prerender-false": "cd tests/fixtures/angular-19-prerender-false && npm ci",
     "pretest": "run-s pretest:*",
     "test": "node --test"
   },