[ci] Update expectation of validation helper spec

To spare myself from writing explanations;-) :

"WARNING: Using `expect { }.not_to raise_error(SpecificErrorClass)` risks false positives, since literally any other error would cause the expectation to pass, including those raised by Ruby (e.g. NoMethodError, NameError and ArgumentError), meaning the code you are intending to test may not even get reached. Instead consider using `expect {}.not_to raise_error` or `expect { }.to raise_error(DifferentSpecificErrorClass)`. This message can be suppressed by setting: `RSpec::Expectations.configuration.on_potential_false_positives = :nothing`. Called from /vagrant/src/api/spec/helpers/validation_helper_spec.rb:17:in `block (3 levels) in <top (required)>'."

src/api/spec/helpers/validation_helper_spec.rb

@@ -14,7 +14,7 @@
     end
 
     it 'does not raise an exception on valid project names' do
-      expect { valid_project_name!("home:mschnitzer") }.to_not raise_error(ValidationHelper::InvalidProjectNameError)
+      expect { valid_project_name!("home:mschnitzer") }.to_not raise_error
     end
   end
 end