Add ember-try scenarios for Ember 4.12 LTS, 5.12 LTS, and 6.12

.github/workflows/ci.yml

@@ -61,6 +61,10 @@ jobs:
         try-scenario:
           - ember-lts-3.24
           - ember-lts-3.28
+          - ember-lts-4.4
+          - ember-lts-4.12
+          - ember-lts-5.12-failing
+          - ember-6.12-failing
           - ember-classic
           - embroider-safe
           - embroider-optimized

config/ember-try.js

@@ -37,6 +37,41 @@ module.exports = async function () {
           },
         },
       },
+      {
+        name: 'ember-lts-4.12',
+        npm: {
+          devDependencies: {
+            'ember-source': '~4.12.0',
+          },
+        },
+      },
+      {
+        // Needs a build-infrastructure refresh (dummy app initializer wiring
+        // + webpack config) before it can pass. Surfacing regressions here
+        // is still useful — allowedToFail so CI doesn't block on it.
+        name: 'ember-lts-5.12-failing',
+        npm: {
+          devDependencies: {
+            '@ember/string': '^4.0.0',
+            'ember-source': '~5.12.0',
+            'ember-resolver': '^13.0.0',
+          },
+        },
+        allowedToFail: true,
+      },
+      {
+        // Same story as ember-lts-5.12 — build infrastructure needs a
+        // refresh before this can pass cleanly.
+        name: 'ember-6.12-failing',
+        npm: {
+          devDependencies: {
+            '@ember/string': '^4.0.0',
+            'ember-source': '~6.12.0',
+            'ember-resolver': '^13.0.0',
+          },
+        },
+        allowedToFail: true,
+      },
       {
         name: 'ember-classic',
         env: {