Bounty Bot Enhancement: Fixed Label Updates & Slack Integration

[rishyym0927]

🛠 Changes Introduced:

✅ Implemented bounty tracking to update the existing bounty label instead of adding duplicates.
✅ Improved GitHub issue comments to update the existing bounty message instead of creating multiple comments.
✅ Sponsorship history tracking: Each user’s total sponsored developers count is tracked and displayed.
✅ Replaced SLACK_WEBHOOK_URL with SLACK_BOT_TOKEN for better Slack integration.
✅ Improved Slack notifications to reflect the updated bounty amount.
🔥 How It Works:

A user comments /bounty $X on an issue.
The bot updates the issue label to reflect the total bounty.
The bot updates the GitHub comment instead of adding duplicate messages.
The bot tracks the number of developers the user has sponsored.
A Slack message is sent to notify about the bounty.

🔍 Testing Done:

✔ Verified that bounties are correctly updated.
✔ Tested Slack notifications for accuracy.
✔ Ensured the GitHub comment updates correctly.

###Changes Made
-You need to manually add the SLACK_BOT_TOKEN and PERSONAL_ACCESS_TOKENS in secrets under actions

###Screenshots

###FIXES OWASP-BLT/BLT#3767