patch 9.1.1325: tests: not checking error numbers properly

Problem:  tests: not checking error numbers properly.
Solution: Add a trailing comma to avoid matching a different error
          number with the same prefix (zeertzjq)

closes: #17159

Signed-off-by: zeertzjq <zeertzjq@outlook.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/testdir/test_vim9_assign.vim b/src/testdir/test_vim9_assign.vim
index 2294936..960dd71 100644
--- a/src/testdir/test_vim9_assign.vim
+++ b/src/testdir/test_vim9_assign.vim
@@ -383,7 +383,7 @@
   var lines =<< trim END
       const x : number = 3
   END
-  v9.CheckDefExecAndScriptFailure(lines, 'E1059')
+  v9.CheckDefExecAndScriptFailure(lines, 'E1059:')
 enddef
 
 def Test_keep_type_after_assigning_null()
@@ -532,8 +532,8 @@
   lines =<< trim END
       [v1, v2] = [1, 2]
   END
-  v9.CheckDefFailure(lines, 'E1089', 1)
-  v9.CheckScriptFailure(['vim9script'] + lines, 'E1089', 2)
+  v9.CheckDefFailure(lines, 'E1089:', 1)
+  v9.CheckScriptFailure(['vim9script'] + lines, 'E1089:', 2)
 
   lines =<< trim END
       var v1: number