Substitute let! with let

There is no need to force the method’s invocation before each example.

src/api/spec/controllers/trigger_controller_spec.rb

@@ -17,7 +17,7 @@
 
   describe '#rebuild' do
     context 'authentication token is invalid' do
-      let!(:token) { nil }
+      let(:token) { nil }
 
       before do
         post :create, params: { format: :xml }
@@ -28,7 +28,7 @@
     end
 
     context 'when token is valid' do
-      let!(:token) { Token::Rebuild.create(executor: user, package: package) }
+      let(:token) { Token::Rebuild.create(executor: user, package: package) }
 
       before do
         allow(Backend::Api::Sources::Package).to receive(:rebuild).and_return("<status code=\"ok\" />\n")
@@ -41,7 +41,7 @@
 
     context 'when the token is not bound to a package' do
       context 'without a package passed in the parameters' do
-        let!(:token) { Token::Rebuild.create(executor: user) }
+        let(:token) { Token::Rebuild.create(executor: user) }
         let(:expected_response_body) do
           <<~XML
             <status code="bad_request">
@@ -141,7 +141,7 @@
 
     context 'when the token is not bound to a package' do
       context 'without a package passed in the parameters' do
-        let!(:token) { Token::Release.create(executor: user) }
+        let(:token) { Token::Release.create(executor: user) }
         let(:expected_response_body) do
           <<~XML
             <status code="bad_request">
@@ -172,7 +172,7 @@
 
     context 'when the token is not bound to a package' do
       context 'without a package passed in the parameters' do
-        let!(:token) { Token::Service.create(executor: user) }
+        let(:token) { Token::Service.create(executor: user) }
         let(:expected_response_body) do
           <<~XML
             <status code="bad_request">