Application builder option server false does not work

[enten]

Command

run

Is this a regression?

• Yes, this behavior used to work in the previous version

The previous version in which this bug was not present was

No response

Description

In Application builder target options (@angular-devkit/build-angular:application), the option server is declared as below since 19.1.0-next.0:

    "server": {
      "type": "string",
      "description": "The full path for the server entry point to the application, relative to the current workspace.",
      "oneOf": [
        {
          "type": "string",
          "description": "The full path for the server entry point to the application, relative to the current workspace."
        },
        {
          "const": false,
          "type": "boolean",
          "description": "Indicates that a server entry point is not provided."
        }
      ]
    }

But when we specify value false, it throws an error:

Error: Schema validation failed with the following errors:
  Data path "/server" must be string.

Minimal Reproduction

Run command ng run my-app:build with angular.json below that specify option "server": false:

{
  "$schema": "./node_modules/@angular/cli/lib/config/schema.json",
  "version": 1,
  "newProjectRoot": "projects",
  "projects": {
    "my-app": {
      "projectType": "application",
      "root": "",
      "sourceRoot": "src",
      "prefix": "app",
      "architect": {
        "build": {
          "builder": "@angular-devkit/build-angular:application",
          "options": {
            "outputPath": "dist/my-app",
            "index": "src/index.html",
            "browser": "src/main.ts",
            "polyfills": [
              "zone.js"
            ],
            "tsConfig": "tsconfig.app.json",
            "inlineStyleLanguage": "scss",
            "assets": [
              {
                "glob": "**/*",
                "input": "public"
              }
            ],
            "styles": [
              "src/styles.scss"
            ],
            "scripts": [],
            "server": false
        }
      }
    }
  }
}

Exception or Error

Error: Schema validation failed with the following errors:
  Data path "/server" must be string.

Your Environment

Angular CLI: 20.0.0-next.3
Node: 20.11.1
Package Manager: npm 10.2.4
OS: win32 x64

Angular: 20.0.0-next.4
... common, compiler, compiler-cli, core, forms
... platform-browser, platform-server, router

Package                      Version
------------------------------------------------------
@angular-devkit/architect    0.2000.0-next.3
@angular-devkit/core         20.0.0-next.3
@angular-devkit/schematics   20.0.0-next.3
@angular/build               20.0.0-next.3
@angular/cli                 20.0.0-next.3
@angular/ssr                 20.0.0-next.3
@schematics/angular          20.0.0-next.3
rxjs                         7.8.2
typescript                   5.8.2
zone.js                      0.15.0

Anything else relevant?

No response