patch 8.2.1480: Vim9: skip expression in search() gives error

Problem:    Vim9: skip expression in search() gives error.
Solution:   use tv_get_bool() eval_expr_to_bool(). (closes #6729)
diff --git a/src/eval.c b/src/eval.c
index c800139..585975a 100644
--- a/src/eval.c
+++ b/src/eval.c
@@ -326,7 +326,7 @@
 	*error = TRUE;
 	return FALSE;
     }
-    res = (tv_get_number_chk(&rettv, error) != 0);
+    res = (tv_get_bool_chk(&rettv, error) != 0);
     clear_tv(&rettv);
     return res;
 }