peerDeps don't support Ember beta with npm

When I do `ember new` with the master branch of ember-cli (which refers to a beta version of ember-source) and npm 8.5, I am getting this:

```
npm ERR! code ERESOLVE
npm ERR! ERESOLVE unable to resolve dependency tree
npm ERR!
npm ERR! While resolving: foo@0.0.0
npm ERR! Found: ember-source@4.6.0-beta.2
npm ERR! node_modules/ember-source
npm ERR! dev ember-source@"~4.6.0-beta.2" from the root project
npm ERR!
npm ERR! Could not resolve dependency:
npm ERR! peer ember-source@">=3.8.0" from @ember/test-helpers@2.8.1
npm ERR! node_modules/@ember/test-helpers
npm ERR! dev @ember/test-helpers@"^2.8.1" from the root project
npm ERR!
npm ERR! Fix the upstream dependency conflict, or retry
npm ERR! this command with --force, or --legacy-peer-deps
npm ERR! to accept an incorrect (and potentially broken) dependency resolution.
npm ERR!
npm ERR! See /Users/simonihmig/.npm/eresolve-report.txt for a full report.

npm ERR! A complete log of this run can be found in:
npm ERR! /Users/simonihmig/.npm/_logs/2022-07-22T18_14_08_017Z-debug-0.log
```

Seems npm is not considering the beta version a match for `>=3.8.0`!? :thinking:

It's not a problem with `--yarn`.