Simplify the Deployable and BuildSuccessWorker

app/models/concerns/deployable.rb

@@ -7,7 +7,7 @@ module Deployable
     after_create :create_deployment
 
     def create_deployment
-      return unless has_environment? && !has_deployment?
+      return unless has_environment?
 
       environment = project.environments.find_or_create_by(
         name: expanded_environment_name

app/workers/build_success_worker.rb

@@ -22,6 +22,8 @@ class BuildSuccessWorker
   # Therefore we no longer need to create a deployment, after a build succeeded.
   # We're leaving this code for the transition period, but we can remove this code in 11.6.
   def create_deployment(build)
+    return if build.has_deployment?
+
     build.create_deployment.try do |deployment|
       deployment.succeed
     end