Disable spec of pattern matching is experimental since 3.1

spec/ruby/language/pattern_matching_spec.rb

@@ -41,24 +41,26 @@
     end
 
     describe "warning" do
-      before :each do
-        ruby_version_is ""..."3.0" do
-          @src = 'case [0, 1]; in [a, b]; end'
-        end
+      ruby_version_is ""..."3.1" do
+        before :each do
+          ruby_version_is ""..."3.0" do
+            @src = 'case [0, 1]; in [a, b]; end'
+          end
 
-        ruby_version_is "3.0" do
-          @src = '[0, 1] => [a, b]'
-        end
+          ruby_version_is "3.0" do
+            @src = '[0, 1] => [a, b]'
+          end
 
-        @experimental, Warning[:experimental] = Warning[:experimental], true
-      end
+          @experimental, Warning[:experimental] = Warning[:experimental], true
+        end
 
-      after :each do
-        Warning[:experimental] = @experimental
-      end
+        after :each do
+          Warning[:experimental] = @experimental
+        end
 
-      it "warns about pattern matching is experimental feature" do
-        -> { eval @src }.should complain(/pattern matching is experimental, and the behavior may change in future versions of Ruby!/i)
+        it "warns about pattern matching is experimental feature" do
+          -> { eval @src }.should complain(/pattern matching is experimental, and the behavior may change in future versions of Ruby!/i)
+        end
       end
     end