build(deps-dev): bump @angular/core from 20.0.3 to 20.3.18 in /ng20

Bumps [@angular/core](https://github.com/angular/angular/tree/HEAD/packages/core) from 20.0.3 to 20.3.18.
- [Release notes](https://github.com/angular/angular/releases)
- [Changelog](https://github.com/angular/angular/blob/main/CHANGELOG.md)
- [Commits](https://github.com/angular/angular/commits/v20.3.18/packages/core)

---
updated-dependencies:
- dependency-name: "@angular/core"
  dependency-version: 20.3.18
  dependency-type: direct:development
...

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

Author: dependabot[bot]

ng20/package-lock.json

@@ -13,7 +13,7 @@
     "@angular/common": "^20.0.3",
     "@angular/compiler": "^20.0.3",
     "@angular/compiler-cli": "^20.0.3",
-    "@angular/core": "^20.0.3",
+    "@angular/core": "^20.3.18",
     "@angular/elements": "^20.0.3",
     "@types/estree": "^1.0.5",
     "@types/node": "^22.5.5",