patch 8.2.3096: temp files remain after running tests

Problem:    Temp files remain after running tests.
Solution:   Delete the right files. (Dominique Pellé, closes #8509)
diff --git a/src/testdir/test_lambda.vim b/src/testdir/test_lambda.vim
index 60d58c5..e173ea3 100644
--- a/src/testdir/test_lambda.vim
+++ b/src/testdir/test_lambda.vim
@@ -330,6 +330,7 @@
     let caught_932 = 1
   endtry
   call assert_equal(1, caught_932)
+  call delete('Xscript')
 endfunc
 
 " vim: shiftwidth=2 sts=2 expandtab