use the set env_var instead of the dorny action

Author: laraPPr

.github/workflows/test-check_easystacks.yml

@@ -67,7 +67,8 @@ jobs:
 
               # check for missing installations if a file in the easystacks directory is changed
               echo "check for missing installation in changed easystack files"
-              easystack_files=(${{ steps.changes.outputs.changed_files }})
+              easystack_files=(${CHANGED_EASYSTACKS})
+              echo $easystack_files
               
               for easystack_file in ${easystack_files[@]}; do
                   echo "check missing installatios for ${easystack_file}..."