Add a monkey patch to squelch warnings from whitequark/parser

config/initializers/parser_patch.rb

+# frozen_literal_string: true
+
+# This works around unnecessary static-analysis warnings that will be
+# fixed via https://github.com/whitequark/parser/pull/528.
+module Parser
+  class << self
+    def warn_syntax_deviation(feature, version)
+      return if ['2.3.8', '2.4.5', '2.5.3'].include?(version)
+
+      warn "warning: parser/current is loading #{feature}, which recognizes"
+      warn "warning: #{version}-compliant syntax, but you are running #{RUBY_VERSION}."
+      warn "warning: please see https://github.com/whitequark/parser#compatibility-with-ruby-mri."
+    end
+  end
+end