[BUGFIX] only allow feature flag alterations in canary (#6738)

Author: runspired

packages/-build-infra/src/features.js

@@ -1,9 +1,18 @@
 'use strict';
 
+function isCanary() {
+  const version = require('../package.json').version;
+  return version.indexOf('alpha') !== -1;
+}
+
 const requireEsm = require('esm')(module);
 function getFeatures() {
   const { default: features } = requireEsm('@ember-data/canary-features/addon/default-features.js');
 
+  if (!isCanary) {
+    return features;
+  }
+
   const FEATURE_OVERRIDES = process.env.EMBER_DATA_FEATURE_OVERRIDE;
   if (FEATURE_OVERRIDES === 'ENABLE_ALL_OPTIONAL') {
     // enable all features with a current value of `null`