Ensure dependency validation workflow is added to appropriate repositories

[brian-smith-tcril]

Once a workflow for validating dependencies against defined rules is added to .github (see openedx/.github#93), we should use repo_checks to ensure that workflow is added to all appropriate repositories.

Feanil mentioned

repo-tools/edx_repo_tools/repo_checks/repo_checks.py

Line 153 in 430c0ca

class EnsureWorkflowTemplates(Check):

as prior art to reference when implementing this.