Remove unneeded peer declaration

is extraneous, and the embroider/auto-import infra know where to get ember-source from.
It's not _wrong_ to include, but it requires folks' manage their deps correctly -- so we can be a little more forgiving to maintainers by just omitting this.


From PR descriptions elsewhere:

- ember-source: removed because the embroider / auto-import know what we intend - it's not bad to have if someone manages their dep graph correctly, which is easier with pnpm, but not everyone gets it right, and folks have a hard time tracking down errors
- @glimmer/tracking removed because it's a real package, but one we don't want to use. This comes up in embroider/vite where the presence of real packages always takes precedence over virtual packages. This is actually problematic because it can break reactivity in subtle ways, even if a dep graph is correct - allowing duplicates of dependencies, which for the glimmer internals, we don't want.
 

Related:
- cibernox/ember-power-calendar#550
- lifeart/ember-click-outside-modifier#47
- tracked-tools/ember-async-data#854
- warp-drive-data/warp-drive#9986
- ember-animation/ember-animated#779
- tildeio/ember-element-helper#125
- CrowdStrike/ember-headless-form#574
- adopted-ember-addons/ember-sortable#620
- ember-cli/ember-app-blueprint#7
- ember-cli/ember-cli#10697
- ember-cli/ember-addon-blueprint#35
- embroider-build/addon-blueprint#339
- ember-polyfills/ember-functions-as-helper-polyfill#151
- jelhan/ember-style-modifier#312
- jmurphyau/ember-truth-helpers#211
- ember-modifier/ember-modifier#949
- tracked-tools/tracked-toolbox#211
- emberjs/ember-test-helpers#1543
- NullVoxPopuli/ember-resources#1189
- NullVoxPopuli/ember-modify-based-class-resource#20
- universal-ember/kolay#187
- universal-ember/reactiveweb#139
- universal-ember/ember-primitives#471
- universal-ember/docs-support#77

Author: NullVoxPopuli

addon/package.json

@@ -79,7 +79,6 @@
   },
   "peerDependencies": {
     "@ember/test-helpers": ">=3.0.3",
-    "ember-source": ">=4.0.0",
     "qunit": "^2.13.0"
   },
   "publishConfig": {