ng test does not run tests for all projects

# 🐞 Bug report

### Command (mark with an `x`)

- [ ] new
- [ ] build
- [ ] serve
- [X] test
- [ ] e2e
- [ ] generate
- [ ] add
- [ ] update
- [ ] lint
- [ ] extract-i18n
- [ ] run
- [ ] config
- [ ] help
- [ ] version
- [ ] doc

### Is this a regression?

Don't know

### Description

The `ng test` documentation states "When a project name is not supplied, it will execute for all projects". However, this does not appear to be true. Only the tests for a single project are run.


## 🔬 Minimal Reproduction

1. Clone https://github.com/swseverance/my-workspace
2. npm install
3. Run `ng test` and observe how only the tests for the app are run. The tests for the lib are not run.

OR

1. Create a workspace
2. Create an app within the workspace
3. Create a lib within the workspace
4. Run `ng test` and observe how only the tests for the app are run. The tests for the lib are not run.

## 🔥 Exception or Error

N/A

## 🌍 Your Environment

Angular CLI: 11.2.14

Node: 14.17.0

OS: darwin x64


Angular: 11.2.14

... animations, cli, common, compiler, compiler-cli, core, forms

... platform-browser, platform-browser-dynamic, router

Ivy Workspace: Yes

Package                         Version

---------------------------------------------------------

@angular-devkit/architect       0.1102.14

@angular-devkit/build-angular   0.1102.14

@angular-devkit/core            11.2.14

@angular-devkit/schematics      11.2.14

@schematics/angular             11.2.14

@schematics/update              0.1102.14

ng-packagr                      11.2.4

rxjs                            6.6.7

typescript                      4.1.6

**Anything else relevant?**

Beginne mit dem Befehl `ng test` und reproduziere das Verhalten im verknüpften Workspace oder in einem Workspace, der eine App und eine Library enthält. Vergleiche das dokumentierte Verhalten für alle Projekte mit der beobachteten Ausgabe und verifiziere anschließend, dass die Tests für jedes Workspace-Projekt ausgeführt werden, wenn kein Projektname angegeben wird.

Vom Indexierungsmodell aus dem Issue-Text verfasst.