Merge branch 'remove-bootlint' into 'master'

Remove bootlint which takes 1 second of render time on development

Closes #37657

See merge request !14167

app/views/layouts/_bootlint.haml

--# haml-lint:disable InlineJavaScript
-:javascript
-  window.onload = function() {
-    var s=document.createElement("script");s.onload=function(){bootlint.showLintReportForCurrentDocument([], {hasProblems: false, problemFree: false});};s.src="https://maxcdn.bootstrapcdn.com/bootlint/latest/bootlint.min.js";document.body.appendChild(s);
-  }

app/views/layouts/_head.html.haml

@@ -76,4 +76,3 @@
 
   = render 'layouts/google_analytics' if extra_config.has_key?('google_analytics_id')
   = render 'layouts/piwik' if extra_config.has_key?('piwik_url') && extra_config.has_key?('piwik_site_id')
-  = render 'layouts/bootlint' if Rails.env.development?