Data path "" must have required property 'project'.

### Command

generate

### Is this a regression?

- [X] Yes, this behavior used to work in the previous version

### The previous version in which this bug was not present was

_No response_

### Description

Hi

We have two projects that use Angular and Angular CLI. After we've upgraded both projects to Angular 16.x we can't use schematics for one of the projects (second project is fine).
We tried to clear node_modules or cache folders but it didn't help.

### Minimal Reproduction

Any time we try to use schematics we always receive an error:

`ng generate class Test`

### Exception or Error

```text
Schematic input does not validate against the Schema: {"name":"Test","path":"src/app/model"}
Errors:

Data path "" must have required property 'project'.
```

### Your Environment

```text
Angular CLI: 16.1.0
Node: 20.3.0 (Unsupported)
Package Manager: yarn 3.5.1
OS: win32 x64

Angular: 16.1.1
... animations, cdk, common, compiler, compiler-cli, core, forms
... google-maps, localize, material, platform-browser
... platform-browser-dynamic, router

Package Version
---------------------------------------------------------
@angular-devkit/architect 0.1601.0
@angular-devkit/build-angular 16.1.0
@angular-devkit/core 16.1.0
@angular-devkit/schematics 16.1.0
@angular/cli 16.1.0
@schematics/angular 16.1.0
rxjs 7.8.1
typescript 5.0.4
```

### Anything else relevant?

_No response_

Reproduziere den gemeldeten Befehl `ng generate class Test` in der beschriebenen Angular CLI 16.1.0-Umgebung und untersuche den Schematic-Validierungsfehler, der `project` erfordert. Vergleiche die Einrichtung des fehlschlagenden Projekts mit der des funktionierenden Projekts; abgeschlossen ist die Aufgabe, wenn die Klassengenerierung ohne den Schemafehler erfolgreich ist.

Vom Indexierungsmodell aus dem Issue-Text verfasst.