Bump @angular-builders/custom-webpack from 12.1.3 to 18.0.0

Bumps [@angular-builders/custom-webpack](https://github.com/just-jeb/angular-builders/tree/HEAD/packages/custom-webpack) from 12.1.3 to 18.0.0.
- [Release notes](https://github.com/just-jeb/angular-builders/releases)
- [Changelog](https://github.com/just-jeb/angular-builders/blob/master/packages/custom-webpack/CHANGELOG.md)
- [Commits](https://github.com/just-jeb/angular-builders/commits/@angular-builders/[email protected]/packages/custom-webpack)

---
updated-dependencies:
- dependency-name: "@angular-builders/custom-webpack"
  dependency-type: direct:development
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <[email protected]>

package.json

@@ -30,7 +30,7 @@
     "zone.js": "~0.11.4"
   },
   "devDependencies": {
-    "@angular-builders/custom-webpack": "^12.1.3",
+    "@angular-builders/custom-webpack": "^18.0.0",
     "@angular-devkit/build-angular": "^12.2.12",
     "@angular/cli": "^12.2.12",
     "@angular/compiler": "^12.2.12",