chore(deps-dev): bump @angular-builders/custom-webpack

Bumps [@angular-builders/custom-webpack](https://github.com/just-jeb/angular-builders) from 8.4.1 to 9.1.0.
- [Release notes](https://github.com/just-jeb/angular-builders/releases)
- [Commits](https://github.com/just-jeb/angular-builders/compare/@angular-builders/custom-webpack@8.4.1...@angular-builders/custom-webpack@9.1.0)

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

Author: dependabot-preview[bot]

package.json

@@ -63,7 +63,7 @@
     "zone.js": "^0.9.1"
   },
   "devDependencies": {
-    "@angular-builders/custom-webpack": "^8.4.1",
+    "@angular-builders/custom-webpack": "^9.1.0",
     "@angular-devkit/build-angular": "^0.803.26",
     "@angular/cli": "^8.3.25",
     "@angular/compiler-cli": "^8.1.2",