fix(docs-infra): remove polyfill web-animations since we use Angular > 6 and we don't use `AnimationBuilder` (#28514)

PR Close #28514

aio/package.json

@@ -93,7 +93,6 @@
     "core-js": "^2.4.1",
     "rxjs": "^6.3.0",
     "tslib": "^1.9.0",
-    "web-animations-js": "^2.2.5",
     "zone.js": "^0.8.26"
   },
   "devDependencies": {

aio/src/ie-polyfills.js

@@ -17,5 +17,5 @@ import 'core-js/es6/set';
 /** IE10 and IE11 requires the following for NgClass support on SVG elements */
 import 'classlist.js';
 
-/** IE10 and IE11 requires the following to support `@angular/animation`. */
-import 'web-animations-js';
+/** Only required if AnimationBuilder is used within the application and using IE/Edge or Safari. */
+// import 'web-animations-js';

aio/yarn.lock

@@ -10623,10 +10623,6 @@ wbuf@^1.1.0, wbuf@^1.7.3:
   dependencies:
     minimalistic-assert "^1.0.0"
 
-web-animations-js@^2.2.5:
-  version "2.3.1"
-  resolved "https://registry.yarnpkg.com/web-animations-js/-/web-animations-js-2.3.1.tgz#3a6d9bc15196377a90f8e2803fa5262165b04510"
-
 web-namespaces@^1.1.2:
   version "1.1.2"
   resolved "https://registry.yarnpkg.com/web-namespaces/-/web-namespaces-1.1.2.tgz#c8dc267ab639505276bae19e129dbd6ae72b22b4"