use pull request target and labelling for triggering deployment from forks

[atlasgong]

https://github.com/glasnt/pull_request_target_demo/blob/96d3be5ebf7dfc818656af005acf0de879f5b45a/.github/workflows/test.yml

https://glasnt.com/blog/pull_request_target_labels/#:~:text=They%20do%20suggest%20a%20work,and%20the%20code%20is%20run

need to be modified to suit our use case and improve security