Update dependency @glint/core to v2.0.0-alpha.12

Author: renovate[bot]

package.json

@@ -73,7 +73,7 @@
     "@embroider/vite": "1.4.3",
     "@eslint/js": "9.39.1",
     "@glimmer/component": "2.0.0",
-    "@glint/core": "2.0.0-alpha.11",
+    "@glint/core": "2.0.0-alpha.12",
     "@glint/environment-ember-loose": "2.0.0-alpha.3",
     "@glint/environment-ember-template-imports": "2.0.0-alpha.3",
     "@glint/template": "1.7.3",