Skip check precompiled assets locally

It is rare we add a new precompiled asset nowadays. For each asset,
sprockets currently checks every asset path directory (we have about 9K)
which is very slow. So disable this check locally.

.gitlab-ci.yml

@@ -68,6 +68,7 @@ variables:
   ELASTIC_URL: "http://elastic:changeme@elasticsearch:9200"
   DOCKER_VERSION: "20.10.1"
   CACHE_CLASSES: "true"
+  CHECK_PRECOMPILED_ASSETS: "true"
   FF_USE_FASTZIP: "true"
 
   # Preparing custom clone path to reduce space used by all random forks

config/environments/test.rb

@@ -23,6 +23,9 @@
 
   # Configure static asset server for tests with Cache-Control for performance
   config.assets.compile = false if ENV['CI']
+  # There is no need to check if assets are precompiled locally
+  # To debug AssetNotPrecompiled errors locally, set CHECK_PRECOMPILED_ASSETS to true
+  config.assets.check_precompiled_asset = Gitlab::Utils.to_boolean(ENV['CHECK_PRECOMPILED_ASSETS'], default: false)
 
   config.public_file_server.enabled = true
   config.public_file_server.headers = { 'Cache-Control' => 'public, max-age=3600' }