docs: remove redirects to no longer existing page (#47929)

This redirect is broken as this page no longer exists.

PR Close #47929

aio/firebase.json

@@ -183,7 +183,6 @@
       // The below paths are referenced in users projects generated by the CLI
       {"type": 301, "source": "/config/tsconfig", "destination": "/guide/typescript-configuration"},
       {"type": 301, "source": "/config/solution-tsconfig", "destination": "https://devblogs.microsoft.com/typescript/announcing-typescript-3-9/#solution-style-tsconfig"},
-      {"type": 301, "source": "/config/app-package-json", "destination": "/guide/strict-mode#non-local-side-effects-in-applications"},
       {"type": 301, "source": "/strict", "destination": "/guide/strict-mode"},
 
       // Use discoverable link for Angular DevTools and redirect to the guide page

aio/ngsw-config.json

@@ -102,7 +102,6 @@
     "!/api/testing/*-*",
     "!/api/upgrade/*/*-(class|decorator|directive|function|interface|let|pipe|type|type-alias|var)",
     "!/api/upgrade/*/index/*",
-    "!/config/app-package-json/{0,1}",
     "!/config/solution-tsconfig/{0,1}",
     "!/config/tsconfig/{0,1}",
     "!/devtools/{0,1}",

aio/tests/deployment/shared/URLS_TO_REDIRECT.txt

@@ -40,7 +40,6 @@
 /api/upgrade/static/downgradeComponent-function.html --> /api/upgrade/static/downgradeComponent
 /api/upgrade/static/index/downgradeComponent-function --> /api/upgrade/static/downgradeComponent
 /api/upgrade/static/UpgradeModule-class --> /api/upgrade/static/UpgradeModule
-/config/app-package-json --> /guide/strict-mode#non-local-side-effects-in-applications
 /config/solution-tsconfig --> https://devblogs.microsoft.com/typescript/announcing-typescript-3-9/#solution-style-tsconfig
 /config/tsconfig --> /guide/typescript-configuration
 /devtools --> /guide/devtools