Update dependency ember-concurrency to v5

Author: renovate[bot]

package.json

@@ -97,7 +97,7 @@
     "ember-cli-inject-live-reload": "2.1.0",
     "ember-cli-notifications": "9.1.0",
     "ember-click-outside": "6.1.1",
-    "ember-concurrency": "4.0.6",
+    "ember-concurrency": "5.1.0",
     "ember-data": "5.7.0",
     "ember-disable-prototype-extensions": "1.1.3",
     "ember-error-route": "0.2.0",