Remote rejected error while trying to pushing to remote repository

Question

I am trying to clone --mirror a cloud source repository and push it to gitlab as a backup mechanism. When I first tried to do it, there was no error. However, when I tested it again after pushing some changes to the cloud source repo, I am getting the below error.

! [remote rejected] origin/feature -> origin/feature (deny updating a hidden ref)  
! [remote rejected] origin/master -> origin/master (deny updating a hidden ref)  
! [remote rejected] origin/test -> origin/test (deny updating a hidden ref) error: failed to push some refs to 'https://gitlab.com/xxxx.git'

Below is the build config file that is triggered every time a backup needs to be taken.

    steps:
  - name: gcr.io/cloud-builders/git
    args:
      - clone
      - '--mirror'
      - 'https://source.developers.google.com/cloud-source-repo'
  - name: gcr.io/cloud-builders/git
    args:
      - fetch
      - '--unshallow'
  - name: gcr.io/cloud-builders/git
    args:
      - '-c'
      - ls
      - cd backup-to-gitlab.git
    entrypoint: bash
  - name: gcr.io/cloud-builders/git
    args:
      - remote
      - set-url
      - '--push'
      - origin
      - >-
        https://xxx:[email protected]/xxxx.git
  - name: gcr.io/cloud-builders/git
    args:
      - push
      - '--mirror'
  - name: gcr.io/cloud-builders/git
    args:
      - '-c'
      - ''
      - cd ..
      - rm
      - '-rf'
      - backup-to-gitlab.git
    entrypoint: bash