Merge branch 'ab/partitioning-startup-flag' into 'master'

Add flag to disable partition check on startup

See merge request gitlab-org/gitlab!37358

config/initializers/postgres_partitioning.rb

@@ -6,7 +6,7 @@
 Gitlab::Database::Partitioning::PartitionCreator.register(AuditEventPartitioned)
 
 begin
-  Gitlab::Database::Partitioning::PartitionCreator.new.create_partitions
+  Gitlab::Database::Partitioning::PartitionCreator.new.create_partitions unless ENV['DISABLE_POSTGRES_PARTITION_CREATION_ON_STARTUP']
 rescue ActiveRecord::ActiveRecordError, PG::Error
   # ignore - happens when Rake tasks yet have to create a database, e.g. for testing
 end