[BUG] Fix pull requests description check for dependabot PRs

[VachaShah]

Describe the bug

Pull requests description check workflow fails on dependabot PRs on the second commit that happens by Dependabot PR actions. The check is added in PR description check workflow to check if the github actor is dependabot, but this fails since for the second commit github actor is not considered as dependabot.

Related component

Other

To Reproduce

1. See https://github.com/opensearch-project/OpenSearch/actions/runs/9066895401/job/24910824890?pr=13642

Expected behavior

The check should pass.

Additional Details

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Host/Environment (please complete the following information):

• OS: [e.g. iOS]
• Version [e.g. 22]

Additional context
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[peternied]

[Triage - attendees 1 2 3 4 5 6 7 8]
@VachaShah Thanks for creating this issue, what do you think about making a pull request to update the workflow?