[ES] Indexer should not trigger data validation

CHANGELOG-EE

@@ -4,6 +4,7 @@ v 8.5.0 (unreleased)
   - Show warning when mirror repository default branch could not be updated because it has diverged from upstream.
   - More reliable wiki indexer
   - GitLab Pages gets support for custom domain and custom certificate
+  - Fix of Elastic indexer. It should not trigger record validation.
 
 v 8.4.4
   - Re-introduce "Send email to users" link in Admin area

lib/elastic/projects_search.rb

@@ -29,7 +29,7 @@ module Elastic
       end
 
       def as_indexed_json(options = {})
-        as_json.merge({
+        as_json(except: :runners_token).merge({
           name_with_namespace: name_with_namespace,
           path_with_namespace: path_with_namespace
         })