Increase CI retries to 4 for these examples

By default it is 2 tries in CI.

spec/lib/gitlab/health_checks/fs_shards_check_spec.rb

@@ -97,6 +97,12 @@ describe Gitlab::HealthChecks::FsShardsCheck do
           }.with_indifferent_access
         end
 
+        # Unsolved intermittent failure in CI https://gitlab.com/gitlab-org/gitlab-ce/issues/31128
+        around(:each) do |example|
+          times_to_try = ENV['CI'] ? 4 : 1
+          example.run_with_retry retry: times_to_try
+        end
+
         it { is_expected.to all(have_attributes(labels: { shard: :default })) }
 
         it { is_expected.to include(an_object_having_attributes(name: :filesystem_accessible, value: 0)) }