Missing ICU argument warnings still appear for keys not present in 5.0.6

• I am on the latest ember-intl version
• I have searched the issues of this repo and believe that this is not a duplicate

5.0.0 added https://github.com/ember-intl/ember-intl/pull/1224 which was intended to suppress missing ICU argument warnings for keys not present in a given localisation file (while still warning if the key is missing for required translations). However it appears to still be warning for the same keys as in 4.2.4 before the PR was merged.

Environment

• Ember Version: 3.9.1
• Ember CLI Version: 3.9.0
• Ember Intl Version: 5.0.6
• Browser(s): N/A
• Node Version: 14.1.0

Steps to Reproduce

1. Config:

module.exports = function() {
  return {
    publicOnly: true,
    requiresTranslation(key, locale) {
      return locale === 'en-us';
    }
  };
};

1. en-us.yaml:

hello: "World"
timeUnits:
  days: "{count, plural, =1 {day} other {days}}"

1. af-za.yaml:

hello: "World"

1. Build log:

[ember-intl] "timeUnits.days" ICU argument missing: "af-za": "count"

[wopian]

ember-intl@5 is the only dependency in yarn.lock. Will create an empty app.

[jasonmit]

5.0.7 corrects the behavior.