Move the `a new user email` shared example to the Emails::Profile spec

This shared example was only used by this spec so having it in a
separate file provided no benefit, at the cost of clarity. This also
reduces the three `it` blocks into a single test with
`aggregate_failures`.

spec/mailers/emails/profile_spec.rb

@@ -5,6 +5,16 @@ describe Notify do
   include EmailSpec::Matchers
   include_context 'gitlab email notification'
 
+  shared_examples 'a new user email' do
+    it 'is sent to the new user with the correct subject and body' do
+      aggregate_failures do
+        is_expected.to deliver_to new_user_address
+        is_expected.to have_subject(/^Account was created for you$/i)
+        is_expected.to have_body_text(new_user_address)
+      end
+    end
+  end
+
   describe 'profile notifications' do
     describe 'for new users, the email' do
       let(:example_site_path) { root_path }

spec/support/notify_shared_examples.rb

@@ -136,20 +136,6 @@ shared_examples 'an answer to an existing thread with reply-by-email enabled' do
   end
 end
 
-shared_examples 'a new user email' do
-  it 'is sent to the new user' do
-    is_expected.to deliver_to new_user_address
-  end
-
-  it 'has the correct subject' do
-    is_expected.to have_subject /^Account was created for you$/i
-  end
-
-  it 'contains the new user\'s login name' do
-    is_expected.to have_body_text /#{new_user_address}/
-  end
-end
-
 shared_examples 'it should have Gmail Actions links' do
   it { is_expected.to have_body_text '<script type="application/ld+json">' }
   it { is_expected.to have_body_text /ViewAction/ }