patch 9.0.2088: Vim9: still allows abstract static methods

Problem:  Vim9: still allows abstract static methods
          (after v9.0.2084, v9.0.2085 and v9.0.2087)
Solution: Disallow abstract static methods

closes: #13479

Signed-off-by: Yegappan Lakshmanan <yegappan@yahoo.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/testdir/test_vim9_class.vim b/src/testdir/test_vim9_class.vim
index 65fa977..1f639e2 100644
--- a/src/testdir/test_vim9_class.vim
+++ b/src/testdir/test_vim9_class.vim
@@ -5607,15 +5607,13 @@
   v9.CheckSourceFailure(lines, 'E1371: Abstract must be followed by "def"', 3)
 
   # Use a static abstract method
-  # TODO: this does not fail, so skip it for now
-
-  # lines =<< trim END
-  #   vim9script
-  #   abstract class A
-  #     abstract static def Foo(): number
-  #   endclass
-  # END
-  # v9.CheckSourceFailure(lines, 'E1371: Abstract must be followed by "def"', 3)
+  lines =<< trim END
+    vim9script
+    abstract class A
+      abstract static def Foo(): number
+    endclass
+  END
+  v9.CheckSourceFailure(lines, 'E1371: Abstract must be followed by "def"', 3)
 
   # Type mismatch between abstract method and concrete method
   lines =<< trim END