Add Dependabot configuration for GitHub Actions updates

[DanielAvdar]

Introduce a dependabot.yml file to automate dependency updates for GitHub Actions workflows. Updates are scheduled to run weekly, ensuring the project stays up-to-date with the latest changes.

Motivation and Context

How Has This Been Tested?

Breaking Changes

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Documentation update

Checklist

• I have read the MCP Documentation
• My code follows the repository's style guidelines
• New and existing tests pass locally
• I have added appropriate error handling
• I have added or updated documentation as needed

Additional context

[cclauss]

Duplicate of

• Keep GitHub Actions up to date with GitHub's Dependabot #517 ?

[ihrpr]

Thank you for working on this!

We already have Dependabot Security Updates enabled though the github UI. We prefer to manage the rest of the decencies manually for this repo.