use event sha

.gitea/workflows/render-manifests.yaml

@@ -64,7 +64,7 @@ jobs:
         run: |
           cd ${MAIN_DIR}
 
-          GIT_DIFF=$(git diff --name-only @{u}@{1}..@{u} | xargs -I {} dirname {} | sort -u)
+          GIT_DIFF=$(git diff --name-only ${{ gitea.event.before }}..HEAD | xargs -I {} dirname {} | sort -u)
           CHANGED_DIR=()
 
           echo ">> Checking for changes .."