ci: Ignore error when no file

Author: jcs090218

.github/workflows/docs.yml

@@ -56,6 +56,7 @@ jobs:
 
     - name: Clean up before the build
       working-directory: ${{ env.PATH_DOC }}
+      continue-on-error: true
       run: git rm -r '*'
 
     - name: Build doc artifacts with Hugo