[libxslt] Allow Python deprecation warnings for now

[Nick Wellnhofer <nwellnhof src gnome org>]

commit b5692cd3d9e08b572cade9f3ba77da3abb93d8e9
Author: Nick Wellnhofer <wellnhofer aevum de>
Date:   Mon Aug 29 15:48:09 2022 +0200

    Allow Python deprecation warnings for now
    
    See libxml2 issue #208.

 .gitlab-ci.yml | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
---
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 2ca5355b..d4af61c8 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -27,7 +27,8 @@ gcc:
 gcc:python3:
   extends: .test
   variables:
-    CFLAGS: "-O2"
+    # TODO: Re-enable the warning after libxml2 #208 is fixed.
+    CFLAGS: "-O2 -Wno-error=deprecated-declarations"
     PYTHON: "/usr/bin/python3"
 
 gcc:static: