Update embroider monorepo to v3.4.9 (#8570)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

package.json

@@ -61,8 +61,8 @@
     "@ember/string": "3.1.1",
     "@ember/test-helpers": "3.3.0",
     "@ember/test-waiters": "3.1.0",
-    "@embroider/compat": "3.4.8",
-    "@embroider/core": "3.4.8",
+    "@embroider/compat": "3.4.9",
+    "@embroider/core": "3.4.9",
     "@embroider/webpack": "4.0.0",
     "@glimmer/component": "1.1.2",
     "@glimmer/tracking": "1.1.2",