Use the suppress_warning helper instead of doing it manually

spec/ruby/language/pattern_matching_spec.rb

@@ -11,14 +11,11 @@ ruby_version_is "2.7" do
 
     ruby_version_is "3.0" do
       it "can be standalone assoc operator that deconstructs value" do
-        $VERBOSE, verbose = nil, $VERBOSE
-        begin
+        suppress_warning do
           eval(<<-RUBY).should == [0, 1]
             [0, 1] => [a, b]
             [a, b]
           RUBY
-        ensure
-          $VERBOSE = verbose
         end
       end
     end