Encountering an error while using the BrowserStack GitHub Actions. It seems that the optional parameters github-app and github-token are not being respected, leading to the following error:

Error: Action Failed: Error: Invalid input for 'github-app'. Must be a valid string.

Steps to Reproduce:

1. Set up a GitHub Actions workflow with the following configuration:

- name: BrowserStack GitHub Actions
  uses: browserstack/github-actions@master
  with:
    # Not providing github-app or github-token
    ...

2. Trigger the workflow.

Expected Behavior: The action should run without errors even if github-app and github-token are not provided since they are marked as optional.

Actual Behavior: Receiving an error indicating that github-app must be a valid string, even when it is not provided.

Environment:

GitHub Actions workflow file
Action version: master

Additional Context:

Verified the action's documentation, and it indicates that both github-app and github-token are optional.
This error began occurring after the recent update that added these parameters.