drop support for Ember < 3.28

Author: mansona

.github/workflows/ci.yml

@@ -46,9 +46,6 @@ jobs:
       fail-fast: false
       matrix:
         try-scenario:
-          - ember-lts-3.16
-          - ember-lts-3.20
-          - ember-lts-3.24
           - ember-lts-3.28
           - embroider-safe
           - embroider-optimized

README.md

@@ -40,7 +40,7 @@
 
 ## Compatibility
 
-* Ember.js v3.16 or above
+* Ember.js v3.28 or above
 * Embroider or ember-auto-import 2.0
 
 ## Using Moment.js in Ember Apps & Addons

test-app-3.x/config/ember-try.js

@@ -6,30 +6,6 @@ module.exports = async function () {
   return {
     usePnpm: true,
     scenarios: [
-      {
-        name: 'ember-lts-3.16',
-        npm: {
-          devDependencies: {
-            'ember-source': '~3.16.0',
-          },
-        },
-      },
-      {
-        name: 'ember-lts-3.20',
-        npm: {
-          devDependencies: {
-            'ember-source': '~3.20.0',
-          },
-        },
-      },
-      {
-        name: 'ember-lts-3.24',
-        npm: {
-          devDependencies: {
-            'ember-source': '~3.24.0',
-          },
-        },
-      },
       {
         name: 'ember-lts-3.28',
         npm: {