chore: Included githubactions in the dependabot config

chore: Included githubactions in the dependabot config

This should help with keeping the GitHub actions updated on new releases. This will also help with keeping it secure.

Dependabot helps in keeping the supply chain secure https://docs.github.com/en/code-security/dependabot

GitHub actions up to date https://docs.github.com/en/code-security/dependabot/working-with-dependabot/keeping-your-actions-up-to-date-with-dependabot

https://github.com/ossf/scorecard/blob/main/docs/checks.md#dependency-update-tool
Signed-off-by: naveen <172697+naveensrinivasan@users.noreply.github.com>
Closes: #8180
Pull-request: https://github.com/sqlalchemy/sqlalchemy/pull/8180
Pull-request-sha: ef796e21f30da98c96e804bcdc056a17465525ca

Change-Id: I8252914951985de81dce944c3ab076dedf439cde