Update src/unsupported_feature.rb with a feature that is still unsupported

Author: aibaars

ql/test/query-tests/diagnostics/ExtractionErrors.expected

@@ -1,5 +1,2 @@
 | src/not_ruby.rb:5:25:5:26 | parse error | Extraction failed in src/not_ruby.rb with error parse error | 2 |
-| src/unsupported_feature.rb:2:18:2:20 | parse error | Extraction failed in src/unsupported_feature.rb with error parse error | 2 |
-| src/unsupported_feature.rb:3:13:3:15 | parse error | Extraction failed in src/unsupported_feature.rb with error parse error | 2 |
-| src/unsupported_feature.rb:6:15:6:17 | parse error | Extraction failed in src/unsupported_feature.rb with error parse error | 2 |
-| src/unsupported_feature.rb:7:20:7:22 | parse error | Extraction failed in src/unsupported_feature.rb with error parse error | 2 |
+| src/unsupported_feature.rb:1:6:2:11 | parse error | Extraction failed in src/unsupported_feature.rb with error parse error | 2 |

ql/test/query-tests/diagnostics/src/unsupported_feature.rb

@@ -1,17 +1,3 @@
-class Foo
-  def initialize(...)
-    do_init(...)
-  end
-
-  def do_init(...)
-    really_do_init(...)
-  end
-
-  def really_do_init(bar, baz:, &block)
-    puts bar
-    puts baz
-    block.call
-  end
-end
-
-Foo.new("hello", baz: "world") { || puts "!" }
+case foo
+  in 3 then 5
+end