Bump @angular/cli from 8.3.20 to 8.3.21

Bumps [@angular/cli](https://github.com/angular/angular-cli) from 8.3.20 to 8.3.21.
- [Release notes](https://github.com/angular/angular-cli/releases)
- [Commits](angular/angular-cli@v8.3.20...v8.3.21)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

package.json

@@ -88,7 +88,7 @@
     },
     "devDependencies": {
         "@angular-devkit/build-angular": "^0.803.21",
-        "@angular/cli": "~8.3.20",
+        "@angular/cli": "~8.3.21",
         "@angular/compiler-cli": "^8.2.2",
         "@angular/language-service": "~8.2.14",
         "@types/ajv": "^1.0.0",