pull request message is always built, removing experiment

updater/lib/dependabot/job.rb

@@ -64,10 +64,6 @@ def reject_external_code?
       @reject_external_code
     end
 
-    def build_pull_request_message?
-      experiments.fetch(:build_pull_request_message, false)
-    end
-
     # rubocop:disable Metrics/PerceivedComplexity
     def allowed_update?(dependency)
       allowed_updates.any? do |update|

updater/lib/dependabot/updater.rb

@@ -959,8 +959,6 @@ def handle_parser_error(error)
     # rubocop:enable Metrics/MethodLength
     # rubocop:enable Metrics/CyclomaticComplexity
     def pr_message(dependencies, files)
-      return nil unless job.build_pull_request_message?
-
       Dependabot::PullRequestCreator::MessageBuilder.new(
         source: job.source,
         dependencies: dependencies,

updater/spec/dependabot/updater_spec.rb

@@ -1608,27 +1608,6 @@ def expect_update_checker_with_ignored_versions(versions)
       end
     end
 
-    context "when build_pull_request_message is set" do
-      let(:experiments) { { "build-pull-request-message" => true } }
-
-      it "builds pull request message" do
-        expect(Dependabot::PullRequestCreator::MessageBuilder).
-          to receive(:new).with(
-            source: job.source,
-            files: an_instance_of(Array),
-            dependencies: an_instance_of(Array),
-            credentials: credentials,
-            commit_message_options: {
-              include_scope: commit_message_include_scope,
-              prefix: commit_message_prefix,
-              prefix_development: commit_message_prefix_development
-            },
-            github_redirection_service: "github-redirect.dependabot.com"
-          )
-        updater.run
-      end
-    end
-
     describe "experiments" do
       let(:experiments) do
         { "large-hadron-collider" => true }