fix: add 'skipPipeline' configuration option to perform the backmerge without CI/CD Pipeline

[JustC0des]

To avoid running the CI/CD pipeline on the target branch a new configuration option 'skipPipeline' has been added.
This prevents the CI/CD Pipeline from being triggered in the target branch to avoid e.g. automatic merge requests created in the CI/CD pipeline from being created without any proper changes.

  [
      "@saithodev/semantic-release-backmerge",
      {
        "backmergeBranches": [{from: "prd", to: "qas"}],
        "skipPipeline": true
      }
    ]
  ]