Post-merge-review: Fix template-require-lang-attribute: validate every BCP47 subtag from 'language-tags'#2683

NullVoxPopuli merged 2 commits intoember-cli:masterember-cli/eslint-plugin-ember:masterfrom

johanrd:day_fix/template-require-lang-attributejohanrd/eslint-plugin-ember:day_fix/template-require-lang-attributeCopy head branch name to clipboard