[#1196] Support Dependabot: Update Actions

[gvatsal60]

This pull request introduces configuration for enabling and configuring dependabot[bot] to automatically handle updates for dependencies, GitHub Actions workflows, and DevContainer configurations in this repository.

The changes made include:

• GitHub Actions: Configured Dependabot to monitor and update GitHub Actions workflows, ensuring that CI/CD pipelines are always using the latest versions of actions.
• DevContainers: Configured Dependabot to manage updates to DevContainer configurations, ensuring that development environments stay in sync with any changes to dependencies.

This enhancement aims to automate the process of keeping dependencies, workflows, and development environments up to date, improving security, maintainability, and reducing technical debt.

Related Issue

• This PR addresses the automation improvements discussed in issue Support for Dependabot [bot] in Repository #1196, where we identified the need to streamline updates across the project.

Checklist

• Enable Dependabot for dependencies.
• Configure Dependabot to monitor and update GitHub Actions workflows.
• Configure Dependabot to manage updates for DevContainer configurations.

[gvatsal60]

@samruddhikhandale, could you please review this PR and provide feedback?