Fix CI config

Refs documentacao-e-tarefas/desenvolvimento_e_infra#1171

Signed-off-by: Thiago Matos <thiago@lepidus.com.br>

Author: thiagolepidus

.gitlab-ci.yml

@@ -3,7 +3,7 @@ variables:
 
 include:
   - project: 'documentacao-e-tarefas/modelosparaintegracaocontinua'
-    ref: main
+    ref: stable-3_4_0
     file:
       - 'templates/groups/pkp_plugin.yml'
       - 'templates/groups/omp/unit_tests.yml'