Add Error Handling for Stale Issue Script in GitHub Action

[Ananya54321]

What does this PR do?

This PR adds comprehensive error handling to the script responsible for closing stale issues in the repository. The main updates include:

Error handling for missing GitHub token: Ensures the GITHUB_TOKEN environment variable is set and valid.
Error handling for GitHub API operations: Wrapped all GitHub API operations (issue retrieval, comments, etc.) in try-catch blocks to gracefully handle API failures.
Rate Limit Handling: Catches and logs GitHub API rate limit errors (RateLimitExceededException), allowing the script to pause if needed.
General error handling: Added safeguards to catch and report unexpected errors during script execution.
These changes make the script more robust and ensure it handles any issues gracefully without crashing.

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• This PR fixes a typo or improves the docs (you can dismiss the other checks if that's the case).
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• Did you write any new necessary tests?