Change deprecated usage of rendering without response body

`render nothing: true` has been deprecated.
For more information see [pr](https://github.com/rails/rails/pull/20336)

app/controllers/admin/abuse_reports_controller.rb

@@ -9,6 +9,6 @@ class Admin::AbuseReportsController < Admin::ApplicationController
     abuse_report.remove_user if params[:remove_user]
     abuse_report.destroy
 
-    render nothing: true
+    head :ok
   end
 end

app/controllers/admin/broadcast_messages_controller.rb

@@ -32,7 +32,7 @@ class Admin::BroadcastMessagesController < Admin::ApplicationController
 
     respond_to do |format|
       format.html { redirect_back_or_default(default: { action: 'index' }) }
-      format.js { render nothing: true }
+      format.js { head :ok }
     end
   end
 

app/controllers/admin/keys_controller.rb

@@ -6,7 +6,7 @@ class Admin::KeysController < Admin::ApplicationController
 
     respond_to do |format|
       format.html
-      format.js { render nothing: true }
+      format.js { head :ok }
     end
   end
 

app/controllers/admin/spam_logs_controller.rb

@@ -11,7 +11,7 @@ class Admin::SpamLogsController < Admin::ApplicationController
       redirect_to admin_spam_logs_path, notice: "User #{spam_log.user.username} was successfully removed."
     else
       spam_log.destroy
-      render nothing: true
+      head :ok
     end
   end
 end

app/controllers/admin/users_controller.rb

@@ -135,7 +135,7 @@ class Admin::UsersController < Admin::ApplicationController
 
     respond_to do |format|
       format.html { redirect_back_or_admin_user(notice: "Successfully removed email.") }
-      format.js { render nothing: true }
+      format.js { head :ok }
     end
   end
 

app/controllers/concerns/toggle_subscription_action.rb

@@ -6,7 +6,7 @@ module ToggleSubscriptionAction
 
     subscribable_resource.toggle_subscription(current_user)
 
-    render nothing: true
+    head :ok
   end
 
   private

app/controllers/dashboard/todos_controller.rb

@@ -10,7 +10,7 @@ class Dashboard::TodosController < Dashboard::ApplicationController
 
     respond_to do |format|
       format.html { redirect_to dashboard_todos_path, notice: 'Todo was successfully marked as done.' }
-      format.js { render nothing: true }
+      format.js { head :ok }
     end
   end
 
@@ -19,7 +19,7 @@ class Dashboard::TodosController < Dashboard::ApplicationController
 
     respond_to do |format|
       format.html { redirect_to dashboard_todos_path, notice: 'All todos were marked as done.' }
-      format.js { render nothing: true }
+      format.js { head :ok }
     end
   end
 

app/controllers/groups/group_members_controller.rb

@@ -43,7 +43,7 @@ class Groups::GroupMembersController < Groups::ApplicationController
 
     respond_to do |format|
       format.html { redirect_to group_group_members_path(@group), notice: 'User was successfully removed from group.' }
-      format.js { render nothing: true }
+      format.js { head :ok }
     end
   end
 

app/controllers/profiles/emails_controller.rb

@@ -24,7 +24,7 @@ class Profiles::EmailsController < Profiles::ApplicationController
 
     respond_to do |format|
       format.html { redirect_to profile_emails_url }
-      format.js { render nothing: true }
+      format.js { head :ok }
     end
   end
 

app/controllers/profiles/keys_controller.rb

@@ -27,7 +27,7 @@ class Profiles::KeysController < Profiles::ApplicationController
 
     respond_to do |format|
       format.html { redirect_to profile_keys_url }
-      format.js { render nothing: true }
+      format.js { head :ok }
     end
   end
 

app/controllers/projects/milestones_controller.rb

@@ -68,7 +68,7 @@ class Projects::MilestonesController < Projects::ApplicationController
 
     respond_to do |format|
       format.html { redirect_to namespace_project_milestones_path }
-      format.js { render nothing: true }
+      format.js { head :ok }
     end
   end
 

app/controllers/projects/notes_controller.rb

@@ -44,7 +44,7 @@ class Projects::NotesController < Projects::ApplicationController
     end
 
     respond_to do |format|
-      format.js { render nothing: true }
+      format.js { head :ok }
     end
   end
 
@@ -53,7 +53,7 @@ class Projects::NotesController < Projects::ApplicationController
     note.update_attribute(:attachment, nil)
 
     respond_to do |format|
-      format.js { render nothing: true }
+      format.js { head :ok }
     end
   end
 

app/controllers/projects/project_members_controller.rb

@@ -55,7 +55,7 @@ class Projects::ProjectMembersController < Projects::ApplicationController
       format.html do
         redirect_to namespace_project_project_members_path(@project.namespace, @project)
       end
-      format.js { render nothing: true }
+      format.js { head :ok }
     end
   end
 
@@ -81,7 +81,7 @@ class Projects::ProjectMembersController < Projects::ApplicationController
 
       respond_to do |format|
         format.html { redirect_to dashboard_projects_path, notice: "You left the project." }
-        format.js { render nothing: true }
+        format.js { head :ok }
       end
     else
       if current_user == @project.owner

app/controllers/projects/protected_branches_controller.rb

@@ -39,7 +39,7 @@ class Projects::ProtectedBranchesController < Projects::ApplicationController
 
     respond_to do |format|
       format.html { redirect_to namespace_project_protected_branches_path }
-      format.js { render nothing: true }
+      format.js { head :ok }
     end
   end
 

spec/controllers/projects/raw_controller_spec.rb

@@ -42,7 +42,7 @@ describe Projects::RawController do
         before do
           public_project.lfs_objects << lfs_object
           allow_any_instance_of(LfsObjectUploader).to receive(:exists?).and_return(true)
-          allow(controller).to receive(:send_file) { controller.render nothing: true }
+          allow(controller).to receive(:send_file) { controller.head :ok }
         end
 
         it 'serves the file' do