Move @ember/test-waiters to dependencies (#993)

* Move @ember/test-waiters v3 to dependencies

* Adjust ember-try config and compatibility

* cleanup unnecessary changes

Author: gorner

README.md

@@ -18,7 +18,7 @@
 
 ----
 
-* Ember.js v3.20 or above
+* Ember.js v3.20 through v5.12
 * Ember CLI v3.13 or above
 * Node.js v12 or above
 

package.json

@@ -29,6 +29,7 @@
     "test:all": "ember try:each"
   },
   "dependencies": {
+    "@ember/test-waiters": "^3.1.0",
     "@floating-ui/dom": "^1.6.12",
     "babel-plugin-filter-imports": "^4.0.0",
     "broccoli-funnel": "~3.0.8",
@@ -48,7 +49,6 @@
     "@ember/render-modifiers": "^2.0.5",
     "@ember/string": "^3.1.1",
     "@ember/test-helpers": "~2.9.4",
-    "@ember/test-waiters": "^3.1.0",
     "@embroider/test-setup": "^3.0.0",
     "@glimmer/component": "^1.1.2",
     "@glimmer/tracking": "^1.1.2",

tests/dummy/config/ember-try.js

@@ -32,8 +32,17 @@ module.exports = async function () {
           },
         },
       },
+      {
+        name: 'ember-lts-5.12',
+        npm: {
+          devDependencies: {
+            'ember-source': '~5.12.0',
+          },
+        },
+      },
       {
         name: 'ember-release',
+        allowedToFail: true,
         npm: {
           devDependencies: {
             'ember-source': await getChannelURL('release'),