Avoid loading rspec-parameterized to avoid warnings

for parser which is emitting:

```
warning: parser/current is loading parser/ruby23, which recognizes
warning: 2.3.5-compliant syntax, but you are running 2.3.6.
warning: please see https://github.com/whitequark/parser#compatibility-with-ruby-mri.
```

There's no easy way to disable this, and we're already using the
latest version. This should be harmless anyway.

Gemfile

@@ -325,7 +325,7 @@ group :development, :test do
   gem 'spinach-rerun-reporter', '~> 0.0.2'
   gem 'rspec_profiling', '~> 0.0.5'
   gem 'rspec-set', '~> 0.1.3'
-  gem 'rspec-parameterized'
+  gem 'rspec-parameterized', require: false
 
   # Prevent occasions where minitest is not bundled in packaged versions of ruby (see #3826)
   gem 'minitest', '~> 5.7.0'