Expire cache in IssuablesCountForState every hour

- Update specs

lib/gitlab/issuables_count_for_state.rb

@@ -6,7 +6,7 @@ module Gitlab
     # The name of the Gitlab::SafeRequestStore cache key.
     CACHE_KEY = :issuables_count_for_state
     # The expiration time for the Rails cache.
-    CACHE_EXPIRES_IN = 10.minutes
+    CACHE_EXPIRES_IN = 1.hour
     THRESHOLD = 1000
 
     # The state values that can be safely casted to a Symbol.

spec/lib/gitlab/issuables_count_for_state_spec.rb

@@ -71,7 +71,7 @@ RSpec.describe Gitlab::IssuablesCountForState do
     let_it_be(:user) { create(:user) }
     let_it_be(:group) { create(:group) }
 
-    let(:cache_options) { { expires_in: 10.minutes } }
+    let(:cache_options) { { expires_in: 1.hour } }
     let(:cache_key) { ['group', group.id, 'issues'] }
     let(:threshold) { described_class::THRESHOLD }
     let(:states_count) { { opened: 1, closed: 1, all: 2 } }